Medium, apparatus, and method related to encryption resultant information

ABSTRACT

A disk-shaped recording medium includes a transparent substrate, and an optical recording layer formed on the transparent substrate. A light source emits light. An optical head is operative for applying the light to the optical recording layer from the light source via the transparent substrate, for focusing the light on the optical recording layer, and for reproducing information from the optical recording layer. A position detecting device is operative for detecting at least one of a pit depth and a physical position of information which has a first given relation with a specified address and which is recorded on the recording medium, and for generating first positional information representing at least one of the pit depth and the physical position. A previously-recorded secret code is reproduced from the recording medium. The secret code represents second positional information. The secret code is decoded into the second positional information. The second positional information represents at least one of a predetermined reference pit depth and a predetermined reference physical position. The first positional information and the second positional information are collated, and a check is made as to whether or not the first positional information and the second positional information are in a second given relation. When the first positional information and the second positional information are not in the second given relation, one of outputting of a reproduced signal of the recording medium, operation of a program stored in the recording medium, and decoding of the secret code is stopped.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a Continuation of application Ser. No. 09/796,534filed Mar. 2, 2001, now U.S. Pat. No. 6,674,703 which is a Division ofapplication Ser. No. 09/305,318 filed May 5, 1999, now U.S. Pat. No.6,243,330, which is a Division of application Ser. No. 08/970,162 filedNov. 13, 1997, now U.S. Pat. No. 5,959,948, which is a Continuation ofapplication Ser. No. 08/534,771 filed Sep. 27, 1995, now U.S. Pat. No.5,699,331, which is a Division of application Ser. No. 08/281,337 filedJul. 27, 1994, now U.S. Pat. No. 5,473,584, which is aContinuation-In-Part of application Ser. No. 08/184,117 filed Jan. 21,1994, now U.S. Pat. No. 5,526,328, which is a Continuation-In-Part ofapplication Ser. No. 08/009,709 filed Jan. 27, 1993, now U.S. Pat. No.5,682,360.

Notice: more than one reissue application has been filed for the reissueof U.S. Pat. No. 6,859,427. The reissue applications are the presentdivisional reissue application Ser. No. 11/304,674 filed on Dec. 16,2005, and the parent reissue application Ser. No. 11/272,484 filed Nov.14, 2005.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to an apparatus for recording and reproducinginformation on and from a recording medium.

2. Description of the Prior Art

Japanese published unexamined patent applications 56-163536, 57-6446,57-212642, and 60-70543 disclose a recording medium having both amagnetic recording portion and an optical recording portion.

Japanese published unexamined patent application 2-179951 discloses arecording medium which has an optical recording portion and a magneticrecording portion at opposite sides thereof respectively. Japanesepatent application 2-179951 also discloses an apparatus which includesan optical head facing the optical recording portion of the recordingmedium for reading out information from the optical recording portion amagnetic head facing the magnetic recording portion of the recordingmedium for recording and reproducing information into and from themagnetic recording portion, and a mechanism for moving at least one ofthe optical head and the magnetic head in according with rotation of therecording medium. In the apparatus of Japanese patent application2-179951, during the processing of the information read out from themagnetic recording portion, a decision is made as to whether or not theinformation recorded on the optical recording portion is necessary, anda step of reading out the information from the optical recording portionis executed when the information on the optical recording portion isdecided to be necessary.

SUMMARY OF THE INVENTION

It is an object of this invention to provide an improved recording andreproducing apparatus.

A first aspect of this invention provides a recording and reproducingapparatus for use with a disk-shaped recording medium which includes atransparent substrate and an optical recording layer formed on thetransparent substrate, the apparatus comprising a light source foremitting light; an optical head for applying the light to the opticalrecording layer from the light source via the transparent substrate, forfocusing the light on the optical recording layer, and for reproducinginformation from the optical recording layer; a position detecting meansfor detecting at least one of a pit depth and a physical position ofinformation which has a first given relation with a specified addressand which is recorded on the recording medium, and for generating firstpositional information representing at least said one of the pit depthand the physical position; a reproducing means for reproducing apreviously-recorded secret code from the recording medium, the secretcode representing second positional information, and for decoding thesecret code into the second positional information, the secondpositional information representing at least one of a predeterminedreference pit depth and a predetermined reference physical position; acollating means for collating the first positional information and thesecond positional information, and for checking whether or not the firstpositional information and the second positional information are in asecond given relation; and a stopping means for, in cases where thefirst positional information and the second positional information arenot in the second given relation, stopping at least one of outputting ofa reproduced signal of the recording medium, operation of a programstored in the recording medium, and decoding of the secret code.

A second aspect of this invention provides a recording and reproducingapparatus for use with a disk-shaped recording medium which includes atransparent substrate, and an optical recording layer and a magneticrecording layer formed on the transparent substrate, the apparatuscomprising a light source for emitting light; an optical head forapplying the light to the optical recording layer from the light sourcevia the transparent substrate, for focusing the light on the opticalrecording layer, and for reproducing information from the opticalrecording layer; a magnetic head for recording a signal on the magneticrecording layer or reproducing a signal from the magnetic recordinglayer; a position detecting means for detecting a position of an addressinformation recorded on the recording medium, and for generating firstpositional information representing said detected position of theaddress information; a reproducing means for reproducing apreviously-recorded secret code from the recording medium, the secretcode representing second positional information, and for decoding thesecret code into the second positional information, the secondpositional information representing a predetermined reference position;a collating means for collating the first positional information and thesecond positional information, and for checking whether or not the firstpositional information and the second positional information are in agiven relation; and a stopping means for, in cases where the firstpositional information and the second positional information are not inthe given relation, stopping at least one of outputting of a reproducedsignal of the recording medium, operation, and decoding of the secretcode.

BRIEF DESCRIPTION THE DRAWINGS

FIG. 1 is a block diagram of a recording and reproducing apparatusaccording to a first embodiment of this invention

FIG. 2 is an enlarged view of an optical recording head portion in thefirst embodiment.

FIG. 3 is an enlarged view of a head portion in the first embodiment.

FIG. 4 is an enlarged view of a head portion in the first embodiment asviewed in a tracking direction.

FIG. 5 is an enlarged view of a magnetic head portion in the firstembodiment.

FIGS. 6(a)-6(g) are a timing chart of magnetic recording in the firstembodiment.

FIG. 7 is a sectional view of a recording medium in the firstembodiment.

FIG. 8 is a sectional view of a recording medium in the firstembodiment.

FIG. 9 is a sectional view of a recording medium in the firstembodiment.

FIG. 10 is a sectional view of a recording portion in the firstembodiment.

FIG. 11 is a sectional view of a recording portion in the firstembodiment.

FIG. 12 is a sectional view of a recording portion in the firstembodiment.

FIG. 13 is a sectional view of a recording portion in the firstembodiment.

FIG. 14 is a sectional view of a recording portion in the firstembodiment.

FIG. 15 is a perspective view of a cassette in the first embodiment.

FIG. 16 is a perspective view of a recording and reproducing apparatusin the first embodiment.

FIG. 17 is a block diagram of a recording and reproducing apparatusaccording to the first embodiment.

FIG. 18 is a perspective view of a game machine in the first embodiment.

FIG. 19 is a block diagram of a recording and reproducing apparatusaccording to a second embodiment of this invention.

FIG. 20 is an enlarged view of a magnetic head portion in the secondembodiment.

FIG. 21 is an enlarged view of a magnetic head portion in the secondembodiment.

FIG. 22 is an enlarged view of a magnetic head portion in the secondembodiment.

FIG. 23 is an enlarged view of a recording portion in a third embodimentof this invention.

FIG. 24 is a block diagram of a recording and reproducing apparatusaccording to a fourth embodiment of this invention.

FIG. 25 is an enlarged view of a magnetic recording portion in thefourth embodiment.

FIG. 26 is an enlarged view of a magneto-optical recording portion inthe fourth embodiment.

FIG. 27 is a sectional view of a recording portion in the fourthembodiment.

FIG. 28 is a flowchart of a program in the fourth embodiment.

FIG. 29 is a flowchart of a program in the fourth embodiment.

FIG. 30(a) is a sectional view of conditions where a magneto-opticaldisk is placed in an operable position in the fourth embodiment.

FIG. 30(b) is a sectional view of conditions where a CD is placed in anoperable position in the fourth embodiment.

FIG. 31 is an enlarged view of a magneto-optical recording portion inthe fourth embodiment.

FIG. 32 is a block diagram of a recording and reproducing apparatusaccording to a fifth embodiment of this invention.

FIG. 33 is an enlarged view of a magnetic recording portion in the fifthembodiment.

FIG. 34 is an enlarged view of a magneto-optical recording portion inthe fifth embodiment.

FIG. 35 is an enlarged view of a magneto-optical recording portion inthe fifth embodiment.

FIG. 36 is an enlarged view of a magnetic recording portion in the fifthembodiment.

FIG. 37 is an enlarged view of a magneto-optical recording portion inthe fifth embodiment.

FIG. 38 is a block diagram of a recording and reproducing apparatusaccording to a sixth embodiment of this invention.

FIG. 39 is a block diagram of a magnetic recording portion in the sixthembodiment.

FIG. 40 is an enlarged view of a magnetic field modulating portion inthe sixth embodiment.

FIG. 41 is a top view of a magnetic recording portion in the sixthembodiment.

FIG. 42 is a top view of a magnetic recording portion in the sixthembodiment.

FIG. 43 is an enlarged view of a magnetic recording portion in the sixthembodiment.

FIG. 44 is an enlarged view of a magnetic field modulating portion inthe sixth embodiment.

FIG. 45(a) is a top view of a disk cassette in a seventh embodiment ofthis invention.

FIG. 45(b) is a top view of a disk cassette in the seventh embodiment.

FIG. 46(a) is a top view of a disk cassette in the seventh embodiment.

FIG. 46(b) is a top view of a disk cassette in the seventh embodiment.

FIG. 47(a) is a top view of a disk cassette in the seventh embodiment.

FIG. 47(b) is a top view of a disk cassette in the seventh embodiment.

FIG. 48(a) is a top view of a disk cassette in the seventh embodiment.

FIG. 48(b) is a top view of a disk cassette in the seventh embodiment.

FIG. 49(a) is a top view of a liner and a portion around the liner inthe seventh embodiment.

FIG. 49(b) is a top view of a liner and a portion around the liner inthe seventh embodiment.

FIG. 49(c) is a top view of a liner and a portion around the liner inthe seventh embodiment.

FIG. 50(a) is a top view of a liner and a portion around the liner inthe seventh embodiment.

FIG. 50(b) is a top view of a liner and a portion around the liner inthe seventh embodiment.

FIG. 50(c) is a transversely sectional view of a liner portion in theseventh embodiment.

FIG. 50(d) is a transversely sectional view of a disk cassette in theseventh embodiment.

FIG. 51 is a transversely sectional view of conditions where liner pininsertion is off in the seventh embodiment.

FIG. 52 is a transversely sectional view of conditions where liner pininsertion is on in the seventh embodiment.

FIG. 53(a) is a transversely sectional view of conditions where linerpin insertion is off in the seventh embodiment.

FIG. 53(b) is a transversely sectional view of conditions where linerpin insertion is on in the seventh embodiment.

FIG. 54(a) is a transversely sectional view of conditions where magnetichead mounting is off in the seventh embodiment.

FIG. 54(b) is a transversely sectional view of conditions where magnetichead mounting is on in the seventh embodiment.

FIG. 55(a) is a transversely sectional view of conditions where magnetichead mounting is off in the seventh embodiment.

FIG. 55(b) is a transversely sectional view of conditions where magnetichead mounting in on the seventh embodiment.

FIG. 56 is a top view of a recording medium in the seventh embodiment.

FIG. 57(a) is a transversely sectional view of conditions where linerpin insertion is off in the seventh embodiment.

FIG. 57(b) in a transversely sectional view of conditions where linerpin insertion is on in the seventh embodiment.

FIG. 58 is a sectional view of a liner pin front portion which assumesan off state in the seventh embodiment.

FIG. 59 is a sectional view of a liner pin front portion which assumesan on state in the seventh embodiment.

FIG. 60 is a transversely sectional view of a liner pin which assumes anoff state in the seventh embodiment.

FIG. 61 is a transversely sectional view of a liner pin which assumes anon state in the seventh embodiment.

FIG. 62 is a sectional view of a front portion in the case where a linerpin is off in the seventh embodiment.

FIG. 63 is a sectional view of a front portion in the case where a linerpin is on in the seventh embodiment.

FIG. 64 is a sectional view of a front portion in the case where a linerpin is off in the seventh embodiment.

FIG. 65 is a sectional view of a front portion in the case where a linerpin is on in the seventh embodiment.

FIG. 66 is a sectional view of a front portion in the case where a linerpin is off in the seventh embodiment.

FIG. 67 is a sectional view of a front portion in the case where a linerpin is off and is inactive in the seventh embodiment.

FIG. 68(a) is a top view of a disk cassette in an eighth embodiment ofthis invention.

FIG. 68(b) is a top view of a disk cassette in the eighth embodiment.

FIG. 69(a) is a transversely sectional view of a portion around a linerpin in the case where liner pin insertion is off in the eighthembodiment.

FIG. 69(b) is a transversely sectional view of a portion around a linerpin in the case where liner pin insertion is on in the eighthembodiment.

FIG. 70(a) is a top view of a disk cassette in the eighth embodiment.

FIG. 70(b) in a top view of a disk cassette in the eighth embodiment.

FIG. 70(c) is a top view of a disk cassette in the eighth embodiment.

FIG. 71 is a transversely sectional view of a liner pin and a diskcassette in the eighth embodiment.

FIG. 72(a) is a transversely sectional view of a portion around a linerpin in the eighth embodiment.

FIG. 72(b) is a transversely sectional view of a portion around a linerpin in the case where a conventional cassette is placed in an operableposition in the eighth embodiment.

FIG. 73(a) is a transversely sectional view of a portion around a linerpin in the case where liner pin insertion is off in the eighthembodiment.

FIG. 73(b) is a transversely sectional view of a portion around a linerpin in the case where liner pin insertion is on in the eighthembodiment.

FIG. 74(a) is a transversely sectional view of a portion around a linerpin in the case where liner pin insertion is off in the eighthembodiment.

FIG. 74(b) is a transversely sectional view of a portion around a linerpin in the case where liner pin insertion is on in the eighthembodiment.

FIG. 75 is a top view of a disk cassette in a ninth embodiment of thisinvention.

FIG. 76 Is a transversely sectional view of a portion around a liner pinin the case where liner pin insertion is off in the ninth embodiment.

FIG. 77 is a transversely sectional view of a portion around a liner pinin the case where liner pin insertion is on in the ninth embodiment.

FIG. 78(a) is a transversely sectional view of a portion around a linerpin in the case where liner pin insertion is off in the ninthembodiment.

FIG. 78(b) is a transversely sectional view of a portion around a linerpin in the case where liner pin insertion is on in the ninth embodiment.

FIG. 79(a) is an illustration of a tracking principle which occurs inthe absence of correction in a tenth embodiment of this invention.

FIG. 79(b) is an illustration of a tracking principle which occurs inthe absence of correction in the tenth embodiment.

FIG. 80(a) is a view of tracking conditions of an optical head in thetenth embodiment.

FIG. 80(b) is a view of tracking conditions of an optical head in thetenth embodiment.

FIG. 81(a) is an illustration of an offset amount of an optical track ona disk in the tenth embodiment.

FIG. 81(b) is an illustration of an offset amount of an optical track ona disk in the tenth embodiment.

FIG. 81(c) is an illustration of a tracking error signal in the tenthembodiment.

FIG. 82(a) is a view of tracking conditions of an optical head whichoccur in the absence of correction in the tenth embodiment.

FIG. 82(b) is a view of tracking conditions of an optical head whichoccur in the presence of correction in the tenth embodiment.

FIG. 83 is an illustration of a reference track in the tenth embodiment.

FIG. 84(a) is a side view of a slider in the case of an ON state in thetenth embodiment.

FIG. 84(b) is a side view of a slider in the case of an OFF state in thetenth embodiment.

FIG. 85(a) is a side view of a slider portion in the case where magneticrecording is OFF in the tenth embodiment.

FIG. 85(b) is a side view of a slider portion in the case where magneticrecording is ON in the tenth embodiment.

FIG. 86 is an illustration of the correspondence relation between anaddress and a position on a disk in the tenth embodiment.

FIG. 87 is a block diagram of a magnetic recording portion in aneleventh embodiment of this invention.

FIG. 88(a) is a transversely sectional view of a magnetic head in theeleventh embodiment.

FIG. 88(b) is a bottom view of a magnetic head in the eleventhembodiment.

FIG. 88(c) is a bottom view of another magnetic head in the eleventhembodiment.

FIG. 89 is an illustration of a spiral-shaped recording format in theeleventh embodiment.

FIG. 90 is an illustration of a recording format of a guard band in theeleventh embodiment.

FIG. 91 is an illustration of a data structure in the eleventhembodiment.

FIGS. 92(a)A-92(a)(S) are a timing chart of recording in the eleventhembodiment.

FIGS. 92(b)A-92(b)(S) are a timing chart of simultaneous recording bytwo heads in the eleventh embodiment.

FIG. 93 is a block diagram of a reproducing portion in the eleventhembodiment.

FIGS. 94(a)-94(c) are an illustration of a data arrangement in theeleventh embodiment.

FIG. 95 is a flowchart of traverse control in the eleventh embodiment.

FIG. 96 is an illustration of a cylindrical recording format in theeleventh embodiment.

FIG. 97 is an illustration of the relation between a traverse gearrotation number and a radius in the eleventh embodiment.

FIG. 98 is an illustration of an optical recording surface format in theeleventh embodiment.

FIG. 99 is an illustration of a recording format in the presence ofcompatibility with a lower level apparatus in the eleventh embodiment.

FIG. 100 is an illustration of the correspondence relation between anoptical recording surface and a magnetic recording surface in theeleventh embodiment.

FIGS. 101(a) and 101(b) are a perspective view of a recording medium ina twelfth embodiment of this invention.

FIG. 102 is a perspective view of a recording medium in the twelfthembodiment.

FIGS. 103(a)-103(f) are a transversely sectional view of a recordingmedium which occurs at film forming and printing steps in the twelfthembodiment.

FIGS. 104(a)-104(f) are a transversely sectional view of a recordingmedium which occurs at film forming and printing steps in the twelfthembodiment.

FIG. 105 is a perspective view of a manufacturing system in a statecorresponding to an application step in the twelfth embodiment.

FIGS. 106(a)-106(c) are is a transversely sectional view of a recordingmedium at application and transfer steps in the twelfth embodiment.

FIGS. 107(a)-107(e) are an illustration of steps of manufacturing arecording medium in the twelfth embodiment.

FIGS. 108(a) and 108(b) are a transversely sectional view of a recordingmedium at application and transfer steps in the twelfth embodiment.

FIG. 109 is a perspective view of a manufacturing system in a statecorresponding to an application step in the twelfth embodiment.

FIG. 110 is a block diagram of a recording and reproducing apparatusaccording to a thirteenth embodiment of this invention.

FIG. 111 is a transversely sectional view of a portion around a magnetichead in the thirteenth embodiment.

FIG. 112 is an illustration of the relation between a head gap lengthand an attenuation amount (dB) in the thirteenth embodiment.

FIG. 113 is a top view of a magnetic track in the thirteenth embodiment.

FIG. 114 is a transversely sectional view of a portion around a magnetichead in the thirteenth embodiment.

FIGS. 115(a) and 115(b) are a transversely sectional view of conditionswhere a recording medium is placed in an operable position.

FIG. 116 is an illustration of the relation between a relative noiseamount and a distance between an optical head and a magnetic head in thetwelfth and thirteenth embodiments.

FIG. 117 is a transverse sectional view of a head traverse portion inthe thirteenth embodiment.

FIG. 118 is a top view of a head traverse portion in the thirteenthembodiment.

FIG. 119 is a transversely sectional view of another head traverseportion in the thirteenth embodiment.

FIG. 120 is a transversely sectional view of another head traverseportion in the thirteenth embodiment.

FIG. 121 is an illustration of the intensities of magnetic fieldsgenerated by various home-use appliances.

FIG. 122 is an illustration of a recording format on a recording mediumin the thirteenth embodiment.

FIG. 123 is an illustration of a recording format on a recording mediumin a normal mode in the thirteenth embodiment.

FIG. 124 is an illustration of a recording format on a recording mediumin a variable track pitch mode in the thirteenth embodiment.

FIG. 125 is an illustration of compressing magnetic recorded informationby using a reference table of optical recorded information in thethirteenth embodiment.

FIG. 126 is a transversely sectional view of a head traverse portion inthe thirteenth embodiment.

FIG. 127 is a flowchart of a recording and reproducing program in thethirteenth embodiment.

FIG. 128 is a flowchart of a recording and reproducing program in thethirteenth embodiment.

FIG. 129(a) is an illustration of a noise detecting head in thethirteenth embodiment.

FIG. 129(b) is an illustration of a noise detecting head in thethirteenth embodiment.

FIG. 129(c) is an illustration of a noise detecting head in thethirteenth embodiment.

FIG. 130 is an illustration of a magnetic sensor in the thirteenthembodiment.

FIG. 131 is a sectional view of a recording and reproducing apparatusaccording to a fourteenth embodiment of this invention.

FIGS. 132(a)-132(h) are a time-domain diagram of various signals in thefourteenth embodiment.

FIG. 133 is a perspective view of a cartridge for an optical recordingmedium in the fourteenth embodiment.

FIG. 134 is a block diagram of a recording and reproducing apparatus inthe fourteenth embodiment.

FIGS. 135(a)-135(e) are a time-domain diagram of various signals in thefourteenth embodiment.

FIG. 136 is a block diagram of a recording and reproducing apparatusaccording to a fifteenth embodiment of this invention.

FIG. 137(a) is a perspective view of the fifteenth embodiment in which acartridge is inserted into the apparatus.

FIG. 137(b) is a perspective view of the fifteenth embodiment in whichthe cartridge is fixed.

FIG. 137(c) is a perspective view of the fifteenth embodiment in whichthe cartridge is ejected from the apparatus.

FIG. 138(a) is a perspective view of the fifteenth embodiment in which acartridge is inserted into the apparatus.

FIG. 138(b) is a perspective view of the fifteenth embodiment in whichthe cartridge is fixed.

FIG. 138(c) is a perspective view of the fifteenth embodiment in whichthe cartridge is ejected from the apparatus.

FIG. 139(a) is a sectional view of the fifteenth embodiment in which acartridge is inserted into the apparatus.

FIG. 139(b) is a sectional view of the fifteenth embodiment in which thecartridge is fixed.

FIG. 139(c) is a sectional view of the fifteenth embodiment in which thecartridge is ejected from the apparatus.

FIG. 140 is a block diagram of a recording and reproducing apparatusaccording to a sixteenth embodiment of this invention.

FIG. 141(a) is a perspective view of the sixteenth embodiment in which acartridge is inserted into the apparatus.

FIG. 141(b) is a perspective view of the sixteenth embodiment in whichthe cartridge is fixed.

FIG. 141(c) is a perspective view of the sixteenth embodiment in whichthe cartridge is ejected from the apparatus.

FIG. 142(a) is a perspective view of the sixteenth embodiment in which acartridge is inserted into the apparatus.

FIG. 142(b) is a perspective view of the sixteenth embodiment in whichthe cartridge is fixed.

FIG. 142(c) is a perspective view of the sixteenth embodiment in whichthe cartridge is ejected from the apparatus.

FIG. 143(a) is a sectional view of the sixteenth embodiment in which acartridge is inserted into the apparatus.

FIG. 143(b) is a sectional view of the sixteenth embodiment in which thecartridge is fixed.

FIG. 143(c) is a sectional view of the sixteenth embodiment in which thecartridge is ejected from the apparatus.

FIG. 144(a) is a diagram of a part of an apparatus for making arecording medium in the fourteenth embodiment.

FIG. 144(b) is a diagram of a part of an apparatus for making arecording medium in the fourteenth embodiment.

FIG. 145(a) is a top view of a recording medium in the fourteenthembodiment.

FIG. 145(b) is a top view of a recording medium in the fourteenthembodiment.

FIG. 145(c) is a top view of a recording medium in the fourteenthembodiment.

FIG. 146(a) is a sectional view of a recording medium in the fourteenthembodiment.

FIG. 146(b) is a sectional view of a recording medium in the fourteenthembodiment.

FIG. 147 is a block diagram of an apparatus according to a seventeenthembodiment of this invention.

FIG. 148 is a flowchart of a program in the seventeenth embodiment.

FIG. 149 is a block diagram of an apparatus according to an eighteenthembodiment of this invention.

FIG. 150 is a flowchart of a program in the eighteenth embodiment.

FIG. 151 is a block diagram of an apparatus according to a nineteenthembodiment of this invention.

FIG. 152 is a diagram of an optical address table and a magnetic addresstable in a recording medium in the nineteenth embodiment.

FIG. 153 is a block diagram of an apparatus in the nineteenthembodiment.

FIG. 154(a) is a diagram of an address table of an optical file and amagnetic file in the nineteenth embodiment.

FIG. 154(b) is a diagram of an address link table between two files inthe nineteenth embodiment.

FIG. 155 is a sectional view of an optical recording medium in thenineteenth embodiment.

FIG. 156 is a flowchart of operation of starting up an optical disk inthe nineteenth embodiment.

FIG. 157(a) is a flowchart of a program in a twentieth embodiment ofthis invention.

FIG. 157(b) is a diagram of an address data table of a magnetic file andan optical file in the twentieth embodiment.

FIG. 157(c) is a block diagram of a bug correcting portion in thetwentieth embodiment.

FIG. 158(a) is a flowchart of a program in a twenty-first embodiment ofthis invention.

FIG. 158(b) is a diagram of a data correction table in the twenty-firstembodiment.

FIG. 158(c) is a block diagram of a bug correcting portion in thetwenty-first embodiment.

FIG. 159 is a block diagram of an apparatus according to a twenty-secondembodiment of this invention.

FIG. 160 is a diagram of a file structure in a computer in thetwenty-second embodiment.

FIG. 161 is a flowchart of a program in the twenty-second embodiment.

FIG. 162 is a flowchart of a program in the twenty-second embodiment.

FIG. 163 is a flowchart of a program in the twenty-second embodiment.

FIG. 164(a) is an illustration of a display screen of a main computer inthe twenty-second embodiment.

FIG. 164(b) is an illustration of a display screen of a main computer inthe twenty-second embodiment.

FIG. 164(c) is an illustration of a display screen of a main computer inthe twenty-second embodiment.

FIG. 164(d) is an illustration of a display screen of a main computer inthe twenty-second embodiment.

FIG. 165 is an illustration of a display screen of a computer in thetwenty-second embodiment.

FIG. 166(a) is an illustration of a display screen of a main computer inthe twenty-second embodiment.

FIG. 166(b) is an illustration of a display screen of a main computer inthe twenty-second embodiment.

FIG. 166(c) is an illustration of a display screen of a main computer inthe twenty-second embodiment.

FIG. 166(d) is an illustration of a display screen of a main computer inthe twenty-second embodiment.

FIG. 167(a) is an illustration of a display screen of a sub computer inthe twenty-second embodiment.

FIG. 167(b) is an illustration of a display screen of a sub computer inthe twenty-second embodiment.

FIG. 168 is a diagram of a network in the twenty-second embodiment.

FIG. 169 is an illustration of a display screen of a main computer inthe twenty-second embodiment.

FIG. 170 is an illustration of a display screen of a computer in theseventeenth embodiment.

FIG. 171 is a diagram of a recording medium in the twenty-secondembodiment.

FIG. 172(a) is a perspective view of a magnetic head in the thirteenthembodiment.

FIG. 172(b) is a sectional view of a magnetic head in the thirteenthembodiment.

FIG. 172(c) is a sectional view of a magnetic head in the thirteenthembodiment.

FIG. 173(a) is a perspective view of a magnetic head in the thirteenthembodiment.

FIG. 173(b) is a sectional view of a magnetic head in the thirteenthembodiment.

FIG. 174(a) is a perspective view of a magnetic head in the thirteenthembodiment.

FIG. 174(b) is a sectional view of a magnetic head in the thirteenthembodiment.

FIG. 175(a) is a perspective view of a magnetic head in the thirteenthembodiment.

FIG. 175(b) is a sectional view of a magnetic head in the thirteenthembodiment.

FIG. 176(a) is a perspective view of a noise detection coil in thethirteenth embodiment.

FIG. 176(b) is a sectional view of a noise detection coil in thethirteenth embodiment.

FIG. 177(a) is a perspective view of a noise detection coil in thethirteenth embodiment.

FIG. 177(b) is a block diagram of a noise detection system in thethirteenth embodiment.

FIG. 178(a) is a perspective view of a noise detection coil in thethirteenth embodiment.

FIG. 178(b) is a block diagram of a noise detection system in thethirteenth embodiment.

FIG. 179 is a diagram of frequency spectrums of reproduced signals whichoccur before and after noise cancel in the thirteenth embodiment.

FIG. 180 is a block diagram of a recording and reproducing apparatus inthe twenty-second embodiment.

FIG. 181 is a block diagram of a recording and reproducing apparatusaccording to a twenty-third embodiment of this invention.

FIG. 182(a) is a top view of the recording and reproducing apparatus inthe twenty-third embodiment.

FIG. 182(b) is a top view of the recording and reproducing apparatus inthe twenty-third embodiment.

FIG. 183(a) is a sectional view of the recording and reproducingapparatus in the twenty-third embodiment.

FIG. 183(b) is a sectional view of the recording and reproducingapparatus in the twenty-third embodiment.

FIG. 183(c) is a sectional view of the recording and reproducingapparatus in the twenty-third embodiment.

FIG. 183(d) is a sectional view of the recording and reproducingapparatus in the twenty-third embodiment.

FIG. 183(e) is a sectional view of the recording and reproducingapparatus in the twenty-third embodiment.

FIG. 184(a) is a diagram of a data structure in a recording medium inthe twenty-third embodiment.

FIG. 184(b) is a diagram of a data structure in a recording medium inthe twenty-third embodiment.

FIG. 184(c) is a diagram of a data structure in a recording medium inthe twenty-third embodiment.

FIG. 185(a) is a top view of a recording medium in the twenty-thirdembodiment.

FIG. 185(b) is a sectional view of a recording medium in thetwenty-third embodiment.

FIG. 185(c) is a sectional view of a recording medium in thetwenty-third embodiment.

FIG. 185(d) is a sectional view of a recording medium in thetwenty-third embodiment.

FIG. 185(e) is a sectional view of a recording medium in thetwenty-third embodiment.

FIG. 186(a) is a sectional view of a recording and reproducing apparatusin the twenty-third embodiment.

FIG. 186(b) is a sectional view of a recording and reproducing apparatusin the twenty-third embodiment.

FIG. 186(c) is a sectional view of a recording and reproducing apparatusin the twenty-third embodiment.

FIG. 186(d) is a sectional view of a recording and reproducing apparatusin the twenty-third embodiment.

FIG. 186(e) is a sectional view of a recording and reproducing apparatusin the twenty-third embodiment.

FIG. 187(a) is a sectional view of a recording and reproducing apparatusin the twenty-third embodiment.

FIG. 187(b) is a sectional view of a recording and reproducing apparatusin the twenty-third embodiment.

FIG. 187(c) is a sectional view of a recording and reproducing apparatusin the twenty-third embodiment.

FIG. 187(d) is a sectional view of a recording and reproducing apparatusin the twenty-third embodiment.

FIG. 187(e) is a sectional view of a recording and reproducing apparatusin the twenty-third embodiment.

FIG. 188(a) is a sectional view of a recording and reproducing apparatusin the twenty-third embodiment.

FIG. 188(b) is a sectional view of a recording and reproducing apparatusin the twenty-third embodiment.

FIG. 188(c) is a sectional view of a recording and reproducing apparatusin the twenty-third embodiment.

FIG. 188(d) is a sectional view of a recording and reproducing apparatusin the twenty-third embodiment.

FIG. 188(e) is a sectional view of a recording and reproducing apparatusin the twenty-third embodiment.

FIG. 188(f) is a sectional view of a recording and reproducing apparatusin the twenty-third embodiment.

FIG. 189(a) is a sectional view of a recording and reproducing apparatusin the twenty-third embodiment.

FIG. 189(b) is a sectional view of a recording and reproducing apparatusin the twenty-third embodiment.

FIG. 189(c) is a sectional view of a recording and reproducing apparatusin the twenty-third embodiment.

FIG. 189(d) is a diagram of mathematical relations for calculating atrack pitch in the twenty-third embodiment.

FIG. 190 is a block diagram of a recording and reproducing apparatus inthe twenty-third embodiment.

FIG. 191(a) is a sectional view of a recording and reproducing apparatusin the twenty-third embodiment.

FIG. 191(b) is a sectional view of a recording and reproducing apparatusin the twenty-third embodiment.

FIG. 191(c) is a sectional view of a recording and reproducing apparatusin the twenty-third embodiment.

FIG. 191(d) is a sectional view of a recording and reproducing apparatusin the twenty-third embodiment.

FIG. 191(e) is a sectional view of a recording and reproducing apparatusin the twenty-third embodiment.

FIG. 192(a) is a sectional view of a recording and reproducing apparatusin the twenty-third embodiment.

FIG. 192(b) is a sectional view of a recording and reproducing apparatusin the twenty-third embodiment.

FIG. 192(c) is a sectional view of a recording and reproducing apparatusin the twenty-third embodiment.

FIG. 192(d) is a sectional view of a recording and reproducing apparatusin the twenty-third embodiment.

FIG. 192(e) is a sectional view of a recording and reproducing apparatusin the twenty-third embodiment.

FIG. 193(a) is a top view of a recording and reproducing apparatus inthe twenty-third embodiment.

FIG. 193(b) is a top view of a recording and reproducing apparatus inthe twenty-third embodiment.

FIG. 194(a) is a sectional view of a recording and reproducing apparatusin the twenty-third embodiment.

FIG. 194(b) is a sectional view of a recording and reproducing apparatusin the twenty-third embodiment.

FIG. 194(c) is a sectional view of a recording and reproducing apparatusin the twenty-third embodiment.

FIG. 194(d) is a sectional view of a recording and reproducing apparatusin the twenty-third embodiment.

FIG. 194(e) is a sectional view of a recording and reproducing apparatusin the twenty-third embodiment.

FIGS. 195(a) and 195(b) are a diagram of the relation between a distancefrom a magnetic head and the intensity of a de magnetic field.

FIG. 196(a) is a sectional view of a recording and reproducing apparatusin the twenty-third embodiment.

FIG. 196(b) is a sectional view of a recording and reproducing apparatusin the twenty-third embodiment.

FIG. 196(c) is a sectional view of a recording and reproducing apparatusin the twenty-third embodiment.

FIG. 197 is a top view of a recording and reproducing apparatus in thetwenty-third embodiment.

FIG. 198(a) is a sectional view of a magnetic head in the twenty-thirdembodiment.

FIG. 198(b) is a top view of a magnetic head in the twenty-thirdembodiment.

FIG. 198(c) is a sectional view of a magnetic head in the twenty-thirdembodiment.

FIG. 198(d) is a top view of a magnetic head in the twenty-thirdembodiment.

FIG. 199(a) is a top view of a recording medium in the twenty-thirdembodiment.

FIG. 199(b) is a top view of a recording medium in the twenty-thirdembodiment.

FIG. 199(c) is a sectional view of a recording medium in thetwenty-third embodiment.

FIG. 200 is a block diagram of a recording and reproducing apparatus inthe twenty-third embodiment.

FIG. 201(a) is a sectional view of a recording and reproducing apparatusin the twenty-third embodiment.

FIG. 201(b) is a sectional view of a recording and reproducing apparatusin the twenty-third embodiment.

FIG. 201(c) is a sectional view of a recording and reproducing apparatusin the twenty-third embodiment.

FIG. 201(d) is a sectional view of a recording and reproducing apparatusin the twenty-third embodiment.

FIG. 202 is a block diagram of a recording and reproducing apparatus inthe first embodiment.

FIG. 203(a) is a diagram of the distribution of the frequencies ofoccurrence of periods T, 1.5T, and 2T in the first embodiment.

FIG. 203(b) is a diagram of the distribution of the frequencies ofoccurrence of periods T, 1.5T, and 2T in the first embodiment.

FIG. 204 is a diagram of the relation between the maximum burstcorrection length and the correction symbol number according to the CDstandards.

FIG. 205 is a diagram of the dispersion length of data on a recordingmedium in the first embodiment.

FIG. 206 is a diagram of the relation between the data amount of anerror correction code and the error rate in the first embodiment.

FIG. 207(a) is a diagram of arrangement conversion related tointerleaving in the first embodiment.

FIG. 207(b) is a diagram of the data dispersion length related tointerleaving in the first embodiment.

FIG. 208 is a block diagram of a de-interleaving portion in the firstembodiment.

FIG. 209(a) is a block diagram of an ECC encoder in the firstembodiment.

FIG. 209(b) is a block diagram of an ECC decoder in the firstembodiment.

FIG. 210 is a flowchart of a program in the first embodiment.

FIG. 211 is a block diagram of a recording and reproducing apparatus inthe first embodiment.

FIG. 212(a) is a diagram of arrangement conversion related tointerleaving in the first embodiment.

FIG. 212(b) is a diagram of the data dispersion length related tointerleaving in the first embodiment.

FIG. 213 is a diagram of the distance and the time interval of a CDsubcode.

FIG. 214 is an illustration of a table of the correspondence between amagnetic track and an optical address in the fourteenth embodiment.

FIG. 215 is a block diagram of a subcode sync signal detector and amagnetic recording portion in the fourteenth embodiment.

FIG. 216 is a block diagram of a recording and reproducing apparatus inthe fourteenth embodiment.

FIG. 217 is a block diagram of a recording and reproducing apparatus inthe fourteenth embodiment.

FIG. 218(a) is a time-domain diagram of an optical reproduction syncsignal in the fourteenth embodiment.

FIG. 218(b) is a time-domain diagram of the conditions of magneticrecording operation in the fourteenth embodiment.

FIG. 218(c) is a time-domain diagram of a magnetic record sync signal inthe fourteenth embodiment.

FIG. 218(d) is a time-domain diagram of the conditions of opticalreproducing operation in the fourteenth embodiment.

FIG. 218(e) is a time-domain diagram of an optical reproduction syncsignal in the fourteenth embodiment.

FIG. 218(f) is a time-domain diagram of the conditions of magneticreproducing operation in the fourteenth embodiment.

FIG. 218(g) is a time-domain diagram of a magnetic reproduction syncsignal in the fourteenth embodiment.

FIG. 218(h) is a time-domain diagram of magnetic reproduced data in thefourteenth embodiment.

FIG. 219 is a diagram of a disk eccentricity according to the CDstandards.

FIG. 220 is a diagram of a file structure in the twenty-secondembodiment.

FIG. 221 is a flowchart of a program in the thirteenth embodiment.

FIG. 222(a) is a top view of a recording medium in a cartridge in thetwenty-third embodiment.

FIG. 222(b) is a sectional view of a recording and reproducing apparatusin the twenty-third embodiment.

FIG. 222(c) is a sectional view of a recording and reproducing apparatusin the twenty-third embodiment.

FIG. 222(d) is a sectional view of a recording and reproducing apparatusin the twenty-third embodiment.

FIG. 222(e) is a sectional view of a recording and reproducing apparatusin the twenty-third embodiment.

FIG. 222(f) is a sectional view of a recording and reproducing apparatusin the twenty-third embodiment.

FIG. 223(a) is a sectional view of a recording medium in the twelfthembodiment.

FIG. 223(b) is a diagram of the physical structure of a mediumidentifier in the twelfth embodiment.

FIG. 223(c) is an exploded view of FIG. 223(a).

FIG. 224 is a diagram of a file structure in the twenty-secondembodiment.

FIG. 225 is a diagram of a file structure in the twenty-secondembodiment.

FIG. 226 is a perspective view of a recording and reproducing apparatusin the twenty-third embodiment.

FIG. 227 is a block diagram of a recording and reproducing apparatus inthe twenty-third embodiment.

FIG. 228 is a diagram of a data structure of a video CD for therecording and reproducing apparatus in the twenty third embodiment.

FIG. 229 is a flowchart of operation of the recording and reproducingapparatus in the twenty-third embodiment.

FIG. 230 is a diagram of a selection number table and a menu picturenumber in the recording and reproducing apparatus in the twenty-thirdembodiment.

FIG. 231(a) is a diagram of a data format of a prior art video CD.

FIG. 231(b) is a diagram of a data format of a prior art video CD.

FIG. 232 is a diagram of optical address search information in therecording and reproducing apparatus in the twenty-third embodiment.

FIG. 233 is a diagram of a data structure in the recording andreproducing apparatus in the twenty-third embodiment.

FIG. 234 is a block diagram of a mastering apparatus in the seventeenthembodiment.

FIG. 235(a) is a time-domain diagram of a linear velocity which occursduring a recording process in the seventeenth embodiment.

FIG. 235(b) is a diagram of an address position on an optical disk whichoccurs at a linear velocity of 1.2 m/s in the seventeenth embodiment.

FIG. 235(c) is a diagram of an address position on an optical disk whichoccurs upon a change of a linear velocity from 1.2 m/s to 1.4 m/s in theseventeenth embodiment.

FIG. 236(a) is a diagram of a physical arrangement (layout) of addressesin a legal (legitimate) CD in the seventeenth embodiment.

FIG. 236(b) is a diagram of a physical arrangement (layout) of addressesin an illegally copied CD in the seventeenth embodiment.

FIG. 237(a) is a time-domain of a disk rotation pulse in the seventeenthembodiment.

FIG. 237(b) is a time-domain diagram of a physical position signal inthe seventeenth embodiment.

FIG. 237(c) is a time-domain diagram of address information in theseventeenth embodiment.

FIG. 238 is a diagram of copy protection for a CD in the seventeenthembodiment.

FIG. 239 is a block diagram of a recording and reproducing apparatus inthe seventeenth embodiment.

FIG. 240 is a flowchart of a check on an illegally copied disk in theseventeenth embodiment.

FIG. 241(a) is a diagram of steps for making a CD into which an IDnumber is recorded.

FIG. 241(b) is a diagram of steps for making a prior art: CD.

FIG. 242(a) is a top view of a magnetizing apparatus in the seventeenthembodiment.

FIG. 242(b) is a side view of the magnetizing apparatus in theseventeenth embodiment.

FIG. 242(c) is an enlarged side view of the magnetizing apparatus in theseventeenth embodiment.

FIG. 242(d) is a block diagram of the magnetizing apparatus in theseventeenth embodiment.

FIG. 243 is a diagram of inputting of an ID number in the seventeenthembodiment.

FIG. 244(a) is a time-domain diagram of a constant linear velocity inthe seventeenth embodiment.

FIG. 244(b) is a time-domain diagram of a varying linear velocity in theseventeenth embodiment.

FIG. 244(c) is a diagram of a physical arrangement (layout) of addresseswhich occur at a constant linear velocity in the seventeenth embodiment.

FIG. 244(d) is a diagram of a physical arrangement (layout) of addresseswhich occur upon a change in a linear velocity in the seventeenthembodiment.

FIG. 245(a) is a sectional view of a legal (legitimate) original diskin, the seventeenth embodiment.

FIG. 245(b) is a sectional view of a legal (legitimate) molded disk inthe seventeenth embodiment.

FIG. 245(c) is a sectional view of an illegally copied original disk inthe seventeenth embodiment.

FIG. 245(d) is a sectional view of an illegally copied molded disk inthe seventeenth embodiment.

FIG. 246 is a block diagram of a CD making apparatus and a recording andreproducing apparatus in the seventeenth embodiment.

FIG. 247 is a flowchart of operation in the seventeenth embodiment.

FIG. 248 is a diagram of an arrangement (layout) of addresses in anoriginal disk in the seventeenth embodiment.

FIG. 249 is a block diagram of a recording and reproducing apparatus inthe seventeenth embodiment.

FIG. 250(a) is a sectional view of an illegal disk in the seventeenthembodiment.

FIG. 250(b) is a sectional view of a legal (legitimate) disk in theseventeenth embodiment.

FIG. 250(c) is a diagram of a waveform of an optical reproduced signalin the seventeenth embodiment.

FIG. 250(d) is a diagram of a waveform of a digital signal in theseventeenth embodiment.

FIG. 250(e) is a diagram of an envelope in the seventeenth embodiment.

FIG. 250(f) is a diagram of a waveform of a digital signal in theseventeenth embodiment.

FIG. 250(g) is a diagram of a waveform of a detection signal in theseventeenth embodiment.

FIG. 251 is a diagram of a disk physical arrangement (layout) table inthe seventeenth embodiment.

FIG. 252(a) is a diagram of an address arrangement (layout) in anoptical disk free from an eccentricity in the seventeenth embodiment.

FIG. 252(b) is a diagram of an address arrangement (layout) in anoptical disk with an eccentricity in the seventeenth embodiment.

FIG. 253(a) is a diagram of a tracking variation amount in a legal(legitimate) disk in the seventeenth embodiment.

FIG. 253(b) is a diagram of a tracking variation amount in an illegallycopied disk in the seventeenth embodiment.

FIG. 254(a) is a diagram of an address An in the seventeenth embodiment.

FIG. 254(b) is a diagram of an angle Zn in the seventeenth embodiment.

FIG. 254(c) is a diagram of a tracking amount Tn in the seventeenthembodiment.

FIG. 254(d) is a diagram of a pit depth Dn in the seventeenthembodiment.

FIGS. 255(a)-255(h) are a time-domain diagram of an laser output, a pitdepth, and a reproduced signal in the seventeenth embodiment.

FIG. 256 is a diagram of copy protection effects with respect tooriginal disk making apparatuses in the seventeenth embodiment.

FIG. 257 is a block diagram of an original disk making apparatus in theseventeenth embodiment.

FIG. 258 is a block diagram of an original disk making apparatus in theseventeenth embodiment.

FIG. 259 is a block diagram of an original disk making apparatus in theseventeenth embodiment.

FIG. 260 is a block diagram of an original disk making apparatus in theseventeenth embodiment.

FIG. 261 is a block diagram of an original disk making apparatus in theseventeenth embodiment.

FIG. 262 is a block diagram of an original disk making system in theseventeenth embodiment.

FIG. 263(a) is a diagram of a waveform of a laser output in theseventeenth embodiment.

FIG. 263(b) is a diagram of a waveform of a laser output in theseventeenth embodiment.

FIG. 263(c) is a sectional view of a disk substrate in the seventeenthembodiment.

FIG. 263(d) is a sectional view of a disk substrate in the seventeenthembodiment.

FIG. 263(e) is a sectional view of a molded disk in the seventeenthembodiment.

FIGS. 264(a)-264(h) are a diagram of the relation between a laser recordoutput and a reproduced signal in the seventeenth embodiment.

FIGS. 265(a)-265(j) are a diagram of steps of making an original disk inthe seventeenth embodiment.

FIG. 266(a) is a top view of an original disk in the seventeenthembodiment.

FIG. 266(b) is a sectional view of a press of an original disk in theseventeenth embodiment.

FIGS. 267(a)-267(i) are a diagram of steps of making an original disk inthe seventeenth embodiment.

FIG. 268(a) is a top view of an original disk in the seventeenthembodiment.

FIG. 268(b) is a sectional view of a press of an original disk in theseventeenth embodiment.

FIG. 269 is a flowchart of operation in the seventeenth embodiment.

FIG. 270 is a flowchart of an application software in the seventeenthembodiment.

FIG. 271 is a diagram of display operation in the twenty-secondembodiment.

FIG. 272 is a diagram of display operation in the twenty-secondembodiment.

FIG. 273 is a diagram of display operation in the twenty-secondembodiment.

FIG. 274 is a flowchart of a program for indicating a virtual file in awindow in the twenty-second embodiment.

DESCRIPTION OF THE FIRST PREFERRED EMBODIMENT

With reference to FIG. 1, a recording and reproducing apparatus 1contains a recording medium 2 which includes a laminated structure of amagnetic recording layer 3, an optical recording layer 4, and atransparent layer 5.

During the magneto-optical reproduction, light emitted from a lightemitting section is focused on the optical recording layer 4 by anoptical head 6 and an optical recording block 7, and a magneto-opticallyrecording signal is reproduced from the recording medium 2.

During the magneto-optical recording, laser light is focused on a givenregion of the optical recording layer 4 by the optical head 6 and theoptical recording block 7 so that a temperature at the given regionincreases to or above a Curie temperature of the optical recording layer4. Under these conditions, a magnetic field applied to the given regionof the optical recording layer 4 is modulated by a magnetic head 8 and amagnetic recording block 9 in response to information to be recorded, sothat recording of the information on the optical recording layer 4 isdone.

During the magnetic recording, the magnetic head 8 and the magneticrecording block 9 are used in recording information on the magneticrecording layer 3.

A system controller 10 receives operating information and outputinformation from various circuits, and drives a drive block 11 andexecutes control of a motor 17 and tracking and focusing control withrespect to the optical head 6. The system controller 10 includes amicrocomputer or a similar device having a combination of a CPU, a ROM,a RAM, and an I/O port. The system controller 10 operates in accordancewith a program stored in the ROM.

In the case where an input signal fed from an exterior is required to berecorded, a recording instruction is fed to the system controller 10from an interface 14 or a keyboard 15 in response to the reception ofthe input signal or the operation of the keyboard 15 by the user. Thesystem controller 10 outputs an inputting instruction to an inputsection 12, and also outputs an optical recording instruction to theoptical recording block 7. The input signal, for example, an audiosignal or a video signal, is received by the input section 12 and isconverted by the input section 12 into a digital signal of a givenformat such as a PCM format. The digital signal is fed from the inputsection 12 to an input section 32 of the optical recording block 7,being coded by an ECC encoder 35 for error correction. An output signalof the ECC encoder 35 is transmitted to the magnetic head 8 via anoptical recording circuit 37, and a magnetic recording circuit 29 and amagnetic recording circuit 29 in the magnetic recording block 9. Themagnetic head 8 generates a recording magnetic field responsive to anoptical recording signal, and applies the magnetic field tomagneto-optical material (photo-magnetic material) in a given region ofthe optical recording layer 4. Recording material in a narrower regionof the optical recording layer 4 is heated to a Curie temperature orhigher by laser light applied from the optical head 6, so that thisregion of the optical recording layer 4 undergoes a magnetization changeor transition responsive to the applied magnetic field. Thus, as shownin FIG. 2, narrower regions of the optical recording layer 4 aresequentially magnetized as denoted by arrows 52 while the recordingmedium 2 is rotated and scanned in a direction 51.

During the previously-mentioned recording of information on the opticalrecording layer 4, the system controller 10 receives trackinginformation, address information, and clock information from an opticalhead circuit 39 and an optical reproducing circuit 38 which have beenrecorded on the optical recording layer 4, and the system controller 10outputs control information to the drive block 11 on the basis of thereceived information. Specifically, the system controller 10 feeds acontrol signal to a motor drive circuit 26 to control the rotationalspeed of the motor 17 for driving the recording medium 2 so that arelative speed between the optical head 6 and the recording medium 2will be equal to a given linear velocity.

An optical head drive circuit and an optical head actuator 18 executetracking control responsive to a control signal from the systemcontroller 10 so that a light beam will scan a target track on therecording medium 2. In addition, the optical head drive circuit and theoptical head actuator 18 execute focusing control responsive to acontrol signal from the system controller 10 so that the light beam willbe accurately focused on the optical recording layer 4.

In the case where the access to another track is required, a head movingcircuit 24 and a head moving actuator 23 moves a head base 19 inresponse to a control signal from the system controller 10 so that theoptical head 6 and the magnetic head 8 on the head base 19 will be movedtogether. Thus, the both heads reach equal radial positions on oppositesurfaces of the recording medium 2 which align with a desired track.

A head elevator 20 for the magnetic head 8 is driven by a magnetic headelevating circuit 22 and an elevating motor 21 in response to a controlsignal from the system controller 10. During a time where a diskcassette 42 is being loaded with the recording medium 2 or wheremagnetic recording is not executed, the magnetic head 8 and a slider 41are separated from the magnetic recording layer 3 of the recordingmedium 2 to prevent wear of the magnetic head 8.

As described previously, the system controller 10 feeds various controlsignals to the drive block 11, and thereby executes tracking control andfocusing control of the optical head 6 and the magnetic head 8,elevation control of the magnetic head 8, and control of the rotationalspeed of the motor 17.

A description will now be given of a method of reproducing amagneto-optically recorded signal. As shown in FIG. 2, laser lightemitted from the light emitting section 57 is incident to a polarizationbeam splitter 55, being reflected and directed toward an optical path 59by the polarization beam splitter 55. The laser light travels along theoptical path 59, being incident to a lens 54 and then being focused onthe optical recording layer 4 of the recording medium 2 by the lens 54.In this case, focusing and tracking control is done by driving only thelens 54 through the optical head drive section 18.

As shown in FIG. 2, the magneto-optical material of the opticalrecording layer 4 is in magnetized, conditions depending on the opticalrecorded signal. Thus, the polarization angle of reflected lighttraveling back along an optical path 59a depends on the direction of themagnetization of the optical recording layer 4 due to the Kerr effect.The reflected light is separated from the forward light by thepolarization beam splitter 55, traveling through the polarization beamsplitter 55 and entering another polarization beam splitter 56. Thereflected light is divided by the polarization beam splitter 56 into twobeams incident to light receiving sections 58 and 58a respectively. Thelight receiving sections 58 and 58a convert the incident light beamsinto corresponding electric signals respectively. A subtractor (notshown) derives a difference between the output signals of the lightreceiving sections 58 and 58a. Since the derived difference depends onthe direction of the magnetization of the optical recording layer 4, thesubtractor generates a signal equal to the reproduction of the opticalrecorded signal. In this way, the optical recorded signal is reproduced.

The reproduced signal is fed from the optical head 6 to the opticalrecording block 7, being processed by the optical head circuit 39 andthe optical reproducing 38 and being subjected to error correction by anECC decoder 36. As a result, the original digital signal is recoveredfrom the reproduced signal. The recovered original digital signal is fedto an output section 33. The output section 33 is provided with a memorywhich stores a quantity of the recorded signal (the recordedinformation) which corresponds to a given interval of time. In the casewhere the memory 34 consists of a 1-Mbit IC memory and a compressedaudio signal having a bit rate of 250 kbps is handled, a quantity of therecorded signal which corresponds to a time of about 4 seconds can bestored. In the case of an audio player, if the optical head 6 moves outof tracking by an external vibration, the recovery of tracking in a timeof 4 seconds prevents the occurrence of a discontinuity in a reproducedaudio signal. The reproduced signal is then transmitted from the outputsection 33 to an output section 13 at a final stage. In the case wherethe reproduced signal represents audio information, the reproducedsignal is subjected to PCM demodulation before being outputted to anexternal device as an analog audio signal.

A description will now be given of a magnetic recording mode ofoperation. In FIG. 1, an input signal applied to an input section 12from an external device or an output signal of the system controller 10is transmitted to an input section 21A of the magnetic recording block 9being subjected by the ECC encoder 35 in the optical recording block 7to a coding process such as an error correcting process. The resultantcoded signal is transmitted to the magnetic head 8 via the magneticrecording circuit 29 and the magnetic head circuit 31.

With reference to FIG. 3, the magnetic recorded signal fed to themagnetic head 8 is converted by a winding 40 into a correspondingmagnetic field. The magnetic material of the magnetic recording layer 3is vertically magnetized by the magnetic field as denoted by arrows 61in FIG. 3. In this way, magnetic recording in a vertical direction isdone so that the information signal is recorded on the recording medium2. The recording medium 2 has a vertically magnetized film. As therecording medium 2 is moved along a direction 51, time segments of theinformation signal is sequentially recorded on the magnetic recordingmedium 2. In this case, although the optical recording layer 4 is alsosubjected to the magnetic field, the optical recording layer 4 isprevented from being magnetized by the magnetic field since themagneto-optical material of the optical recording layer 4 has a magneticcoercive force of several thousands to ten thousands of Oe attemperatures below the Curie temperature.

In the case where a portion of the magnetic recording layer 3 whichactually undergoes the magnetic recording process is excessively closeto the optical recording layer 4, the intensity of a magnetic filedapplied to the optical recording layer 4 from the magnetic recordingportion of the magnetic recording layer 3 sometimes reaches a level ofseveral tens to several hundreds of Oe.

Under these conditions, in the case where the temperature of the opticalrecording layer 4 is increased above the Curie temperature formagneto-optical recording, the optical recording layer 4 tends toundergo a magnetization change or transition in response to the magneticfield from the magnetic recording portion of the magnetic recordinglayer 3 so that an error rate increases during the magneto-opticalrecording. To resolve such a problem, it is preferable to provide aninterference layer 81 of a given thickness between the magneticrecording layer 3 and the optical recording layer 4 as shown in FIG. 7.Opposite surfaces of the optical recording layer 4 are provided withprotective layers 82 and 82a to prevent deterioration thereof. The sumof the thickness of the interference layer 81 and the thickness of theprotective layer 82 is equal to an interference interval or distance L.In this case, an attenuation rate is given as 56.4×L/λ where λ denotes amagnetic recording wavelength. When λ=0.5 μm, an interference interval Lof 0.2 μm or greater can provide an adequate level of the effect.

As shown in FIG. 8, a protective layer 82 of a thickness equal to orgreater than the interference interval may be provided between themagnetic recording layer 3 and the optical recording layer 4.

The magnetic recording medium 2 of FIG. 7 was fabricated as follows. Theprotective layer 82 and the interference layer 81 were sequentiallyformed on the optical recording layer 4. Magnetic material such asbarium ferrite was prepared which had vertical anisotropy. Lubricant,binder, and the magnetic material were mixed. The resultant mixture wasapplied to the substrate by spin coat to form the magnetic recordinglayer 3 while a magnetic field was applied to the substrate in thevertical direction of the substrate.

The recording and reproducing apparatus 1 can operate on a ROM disksimilar to a compact disk (CD). FIG. 9 shows an example of a ROM-typerecording medium 2. The recording medium 2 of FIG. 9 was fabricated asfollows. A substrate 5 was provided with pits. A reflecting film 84 ofsuitable material such as aluminum was formed over the pits of thesubstrate 5. Lubricant, binder, and magnetic material were mixed. Theresultant mixture was applied to the reflecting film 84 to form amagnetic recording layer 3 while a magnetic field was applied to thesubstrate 5 in the vertical direction of the substrate 5. The magneticrecording layer 3 had a vertical magnetic recording film. The recordingmedium of FIG. 9 has the function of a CD ROM at one side, and has thefunction of a RAM at the other side. Thus, the recording medium of FIG.9 provides various advantages as described later. In this case, a costincrease results from only adding the magnetic substance to the materialwhich will form a protective film through spin coat similar to thatexecuted to fabricate a currently-used CD. Accordingly, a manufacturingcost increase corresponds to only the cost of the magnetic substance.Since the cost of the magnetic substance is equal to a few percent ofthe manufacturing cost of the recording medium, the cost increase isvery small.

During the magnetic recording, tracking is executed as follows. In FIG.1, the optical head 6 and the optical head circuit 39 reproduce trackinginformation from the recording medium 2. The system controller 10outputs a moving instruction to the head moving circuit 24 in responseto the reproduced tracking information, driving the actuator 23 andthereby moving the head base 19 in the tracking direction. Thus, asshown in FIG. 4, light beam emitted from the optical head 6 is focusedinto a spot 66 near a given optical recording track 65 of the opticalrecording layer 4. The optical head drive section 18 for driving theoptical head 6 is mechanically coupled with the magnetic head 8 via thehead base 19 and the head elevator 20. Therefore, the magnetic head 8moves in the tracking direction as the optical head 6 moves. Thus, whenthe optical head 6 is aligned with the given optical track 66, themagnetic head 8 is moved into alignment with a given magnetic track 67which extends at the opposite side of the optical track 66. Guard bands68 and 68a are provided at opposite sides of the magnetic track 67. Asshown in FIG. 5, when the position of the optical head 6 is controlledso as to scan a given Tn-th optical track 65, the magnetic head 8 runsalong a given Mm-th magnetic track 67 extending at the opposite side ofthe optical track 65. In this case, the drive system for the opticalhead 6 suffices and it is unnecessary to provide a tracking controldevice for the magnetic head 8. Furthermore, it is unnecessary toprovide a linear sensor required in a conventional magnetic disk drive.

A description will now be given of a method of accessing an opticaltrack and a magnetic track. The optical head 6 is subjected to trackingtogether with the magnetic head 8. Therefore, in the case where there isa difference in radial direction between an optical track currentlyexposed to an information recording or reproducing process from thelower surface and a magnetic track desired to be accessed from the uppersurface, the two tracks can not be accessed at the same time. In thecase of a data signal, this access problem causes only a delay in accessand does not cause a significant problem. In the case of a continuoussignal such as an audio signal or a video signal, an interruption isgenerally unacceptable. Thus, the magnetic recording can not be executedduring an optical recording or reproducing process at a normal speed.This embodiment uses the system in which the memory 34 is provided inconnection with the input section 32 and the output section 33 to storea quantity of a signal which corresponds to an interval equal to severaltimes the maximum access time of magnetic recording.

As shown in FIG. 6, the rotation speed of the recording medium 2 isincreased by n times during a recording or reproducing process, andthereby an optical recording or reproducing time T is shortened to 1/nas compared with that of a normal speed and becomes equal to T1 and T2.Thus, a time T0 between t2 and t5 which equals to n−1 times therecording or reproducing time is a margin time. In the case where amagnetic track is accessed during an access time Ta between t2 and t3 inthe margin time T0 and a magnetic recording or reproducing process isdone during a recording or reproducing time TR between t3 and t4 andwhere head return or motion to an original optical track or a nextoptical track is done during a return time Tb between t5 and t6, accessfor the optical recording and access for the magnetic recording can beexecuted in time division by a single head moving section. In this case,the capacity of the memory 34 is chosen so that the memory 34 can storea continuous signal during the margin time T0.

Access to a track by the magnetic head 8 will now be described withreference to FIG. 6 and FIGS. 10-16. A cassette 42 shown in FIG. 15includes the recording medium 2. The cassette 42 is inserted into arecess in a casing of the recording and reproducing apparatus 1 shown inFIG. 16. Then, as shown in FIG. 10, a light beam emitted from theoptical head 6 is focused on an optical track 65 in a TOC region on arecording surface of the recording medium 2, and TOC information isreproduced. Index information is recorded in the TOC region. During thereproduction of the TOC information, the magnetic head 8 travels on amagnetic track 67 at the opposite side of the optical track 65 so thatmagnetically recorded information is reproduced from the magnetic track67. In this way, during the first process, information is reproducedfrom the optical track in the TOC region of the recording medium 2, andsimultaneously information is reproduced from the magnetic track. Theinformation reproduced from the magnetic track represents the contentsof previous access, conditions at the end of previous operation, orothers. As shown in FIG. 16, the contents of the reproduced informationare indicated on a display 16.

In the case of audio information, a final music number, an elapsed timeof an interruption thereof, a reserved music number, or others areautomatically recorded on the magnetic recording region. When themagnetic recording medium 2 is inserted into the recording andreproducing apparatus 1 again, information of a table of contents isreproduced from the optical track 65 and also information at the end ofprevious operation is reproduced from the magnetic track 67 aspreviously described. The reproduced information is indicated on thedisplay 16 as shown in FIG. 16. FIG. 16 shows conditions where theprevious access end time, the operator name, the final music number, theelapsed time of an interruption, the previously preset music order, andthe music number are recorded and indicated. Specifically, “Continue?”is indicated. When “Yes” is inputted as a reply, the music starts to bereproduced from a point at which the previous operation ends. When “No”is inputted as a reply, the music is reproduced in the preset order. Inthis way, the user is enabled to enjoy the automatic reproduction of thepreviously-interrupted contents as they are, or to listen the music inthe desired order.

In the case of a CD ROM game device 18 shown in FIG. 18, the previouslyinterrupted game contents, for example, the stage number, the acquiredpoints, and the item attainment number, are recorded and reproduced.Upon the start of the game a certain time after the previous end of thegame, the game can be started from the place same as the previous placeand the conditions same as the previous conditions. This advantage cannot be provided by a prior art CD ROM game device.

The above-mentioned simple method of accessing the magnetic track in theTOC region has an advantage in that the structure is simple and the costis low although the memory capacity is small.

A description will now be given of access to a track outside the TOCregion. FIG. 11 shows conditions where the optical head 6 accesses agiven optical track 65a. At this time, the magnetic head 8 which movestogether with the optical head 6 accesses a magnetic track 67a at theopposite side of the optical track 65a. In the case where requiredinformation is on a magnetic track 67b separate from the magnetic track67a, it is necessary to move the magnetic head 8 to the magnetic track67b. In this case, as previously described with reference to FIG. 6, itis necessary to complete the head movement, the recording, and the headreturn in a margin time T0. List information representing thecorrespondence between the magnetic track numbers and the optical tracknumbers is previously recorded on a TOC region or another given regionof the optical recording layer 4. The list information is read out, andthe optical track number corresponding to the, required magnetic tracknumber is calculated by referring to the list information. Then, asshown in FIG. 12, during an access time Ta, the head base 19 is movedand fixed so that the optical head 6 can access an optical track 65bcorresponding to the calculated optical track number. Thus, the magnetichead 8 will follow the required magnetic track 67b. In this way, themagnetic recording or reproduction can be executed. In this case, asshown in FIG. 13, while the optical track 65a is being scanned, themagnetic head 8 remains lifted to an upper position well separated fromthe magnetic recording layer 3 by the elevating motor 21. In addition,during the access time Ta, as denoted by the character “ω” in FIG. 6,the rotational speed of the motor 17 is lowered. While the rotationalspeed remains low, the magnetic head 8 is moved downward into contactwith the magnetic recording layer 3. Thereby, it is possible to preventthe magnetic head 8 from being damaged. During an interval TR, therotational speed is increased and the magnetic recording is done. Duringan interval T, the rotational speed is lowered and the magnetic head 8is lifted. Then, the rotational speed is increased again, and theoptical head 6 is returned to the optical track 65a as shown in FIG. 13.During an interval T2, optical recording and reproduction is done. Sincethe data stored in the memory 34 is reproduced during the margin timeT0, the reproduced signal or the reproduced music will not beinterrupted. As shown in FIG. 14, during access to the TOC region, themagnetic head 8 is not moved downward in the presence of an instructionrepresenting that magnetic recording on the TOC region is unnecessary.Thereby, even if a recording medium 2 having no magnetic recording layer3 is inserted into the recording and reproducing apparatus, the magnetichead 8 can be prevented from contacting the recording medium 2 and beingthus damaged. In this way, the execution of the upward and downwardmovement of the magnetic head 8 during a period of the occurrence of alowered rotational speed provides an advantage such that a damage to themagnetic head 8 can be prevented and wear thereof can be remarkablyreduced.

FIG. 15 shows the cassette 42 which contains the recording medium 2. Thecassette 42 is provided with a shutter 88, a magnetic recordingprevention click 89, and an optical recording prevention click 89a. Themagnetic recording prevention and the optical recording prevention canbe set separately. In the case of a ROM cassette, only a magneticrecording prevention click 89a is provided thereon.

FIG. 17 shows a recording and reproducing apparatus for reproduction ofoptically recorded information. An optical recording circuit and an ECCencoder are omitted from an optical recording block 7 in the recordingand reproducing apparatus of FIG. 17 as compared with that of FIG. 1.The recording and reproducing apparatus of FIG. 17 additionally includesa magnetic head elevator 20, a magnetic head 8, and a magnetic recordingblock 9 as compared with a conventional reproduction player such as a CDplayer. All the parts of the recording and reproducing apparatus of FIG.17 can be used in common to the parts of the recording and reproducingapparatus of FIG. 1. Their costs are very low relative to opticalrecording parts, and the resultant cost increase is small. Although thememory capacity is smaller than that of a floppy disk, information canbe recorded and reproduced on and from a ROM-type recording medium atsuch a low cost. Thus, in the case of a game device or a CD playerrequiring only a small memory capacity, various advantages are providedas previously described. According to estimation, in the case of arecording medium disk having a diameter of 60 mm, a magnetic recordingmemory capacity of about 1 KB to 10 KB is obtained by using a magnetichead for modulating a magnetic field. A memory of a 2-KB or 8-KB SRAM isprovided on a typical game ROM IC, and thus the above-mentioned memorycapacity is sufficient. Thus, there is an advantage such that therecording medium disk can replace a ROM IC.

The error correction encoder 35 and the error correction decoder 36 ofFIG. 1 will now be described in detail. With respect to a normalmagnetic disk such as a 3.5-inch floppy disk of the 2HD type or the 2DDtype, an error correcting process is not executed. In the case of the3.5-inch 2HD floppy disk, the error rate is close to 10⁻¹² when recordand reproduction are done at 135 TPI. Accordingly, in the case where thefloppy disk is used in a cartridge, the disk is less contaminated orinjured so that there hardly occurs a burst error. Therefore, it isunnecessary to execute error correction including interleaving. A CD ROMhaving a magnetic recording layer on a medium front surface or backsurface is used without any cartridge. In the case of such a CD ROM,dust and a scratch cause a burst error.

The recording medium of this invention is designed, so that Hc=1900 Oe.The magnetic recording layer is applied to the CD label side in whichthe space loss by the print layer and the protective layer is 9 to 10micrometers. During experiments, this recording medium was subjected 10⁶times to recording and reproducing processes by a magnetic head of theamorphous lamination (multilayer) type through MFM modulation at 500BPI, that is, a wavelength of 50 μm, and the frequencies of appearanceof respective pulse widths were measured. FIG. 203(a) and FIG. 203(b)show the results of the measurement. FIG. 203(a) shows the results ofthe measurement of the pulse with up to 1 ms. FIG. 203(b) shows theenlarged measurement data of the pulse width up to 100 μs.

As noted by the arrow 51a of FIG. 203(a), some burst errors having longperiods occur with respect to sampling of 10⁶ times. Thus, interleavingis done as shown in the error correcting portion 35 of FIG. 1 or FIG.202. Specifically, as shown in FIGS. 207(a) and 207(b), ECC encoding isdone before or after the interleaving.

As shown in FIG. 203(b), the intervals of 1T, 1.5T, and 2T in MFMmodulation are adequately large. Thus, it is thought that an error rateof about 10⁻⁵ to 10⁻⁶ occurs under bad conditions.

Burst errors more frequently occur in comparison with a disk in acartridge such as a floppy disk. In addition, more random error occur byseveral orders. Accordingly, to use such a recording medium without anycartridge, interleaving and good correction are necessary. As the amountof error correction code increases, the degree of redundancy increasesbut the amount of data decreases. A target value of burst errorcountermeasure is determined with reference to the allowable standard(reference) of scratch of a CD.

The probability of the occurrence of a scratch on the optical recordingsurface is equal to that on the label surface. FIG. 204 shows theability of error correction with respect to a scratch on the opticalrecording layer of a CD. In the case of correction of 4 symbols, it ispossible to compensate for a scratch corresponding to 14 frames or less,that is, a scratch having a length of 2.38 mm or less. The interleavinglength is set to correspond to 108 frames, that is, a length of 18.36mm. Thus, with respect to the magnetic recording layer, it is necessaryto provide error correcting ability containing interleaving which cancompensate for a scratch having a length of 2.38 mm or less. In thiscase, an optimal degree of redundancy is attained. Therefore, even ifthe magnetic recording portion of this recording medium is subjected tosuch a scratch, the resultant errors are corrected by the encoder 35 andthe decoder 36 so that data errors do not occur. Thus, the user canhandle the recording medium of this invention similarly to a CD or a CDROM.

According to this invention, it was experimentally confirmed that ascratch of 7 mm at an outermost portion and a scratch of 3 mm at aninnermost portion were compensated under conditions where theinterleaving corresponded to a length of 18 mm or more and Reed-Solomonerror correction was used, and the degree of redundancy corresponded toa factor of 1.2 in the range of upper and lower 10% as shown in FIG.206. Thus, a scratch of 2.38 mm could be compensated under theseconditions. The interleaving length Ld on the data is defined as shownin FIG. 205, and a physical interleaving length LM on the medium surfaceis set to 18 mm or more. In addition, as shown in FIG. 206, the dataamount of error correction code such as Reed-Solomon code is set equalto the original data amount multiplied by a value of 0.08 to 0.32.Thereby, it is possible to attain error correction against a scratchwhich is comparable with that in a CD.

FIG. 202 shows the details of the error correction encoder 35 and theerror correction decoder 36. The magnetic record signal is ECC-encodedby a Reed-Solomon encoder 35a for executing an operation of Reed-Solomonencoding. A transverse-direction parity 452a is added to the ECC-encodeddata sequence. In an interleaving portion 35b, according to aninterleaving table of FIGS. 207(a) and 207(b), the data sequence is readout in a longitudinal direction 51b so that the original data isseparated by a dispersion distance L on the recording medium surface asshown in FIG. 207(b).

Even in the presence of a burst error, the data can be recovered inresponse to the parity 452. When the dispersion length L is set to 19 mmor more, an error compensating ability comparable to that of a CD can beattained. With respect to the reproduced signal, in a de-interleavingportion 36b shown in FIG. 208, the data is mapped onto a RAM 36x and isthen subjected to address conversion reverse to that of FIGS. 207(a) and207(b), so that the data is returned to the original arrangement(sequence).

Then, the reproduced data is processed by a Reed-Solomon decoder 36a ofFIG. 209(b) as follows. As shown in FIG. 210, at a step 452b, P and Qparities and the data are inputted. At a step 452c, syndromes S1 and S2are calculated. Only when S1=S2=0 at a step 452d, an advance to a step452g is done so that the data is outputted. In the presence of an error,calculation for error correction is executed at a step 452e. Only whenthe error is corrected by a step 452f, the data is outputted at the step452g. In this invention, the demodulation clock speed (rate), in themagnetic recording and reproducing portion is equal to 30 Kbps (seeFIGS. 203(a) and 203(b) which is a data rate equal to 1/100 of the CDdata rate. In view of this small data processing amount, errorcorrection of the optical reproduced signal is done by an exclusive ICwhile the signal processing in the error correction encoder 35 and theerror, correction decoder 36 of FIG. 202 is executed by a microcomputer10a in the system controller 10 through a time division technique.Specifically, the interleaving of FIGS. 207(a) and 207(b) and the errorcorrection in FIG. 210 are done by the microcomputer 10a.

The microcomputer 10a is of the 8-bit or 16-bit type driven by a clocksignal having a several tens of MHz. As shown in FIG. 210, two routines,that is, a system control routine 452p and an error correcting routine452a are executed in time division. Specifically, the system controlroutine is started as a step 452h, and motor rotation control isexecuted at a step 452j. At a step 452k, control for head movement andcontrol for an actuator such as a traverse are executed. At a step 452m,indication of a drive and control of an input/output drive system areexecuted. Only in the case where one work unit for the system control iscompleted at a step 452n and error correction is required, entrance intothe error correction routine 452q is done. At a step 452r, interleavingor deinterleaving is executed which has been described with reference toFIG. 207(a) and 207(b). Steps 452b-452g execute calculations for thepreviously-mentioned error correction.

In this invention, the magnetic recording has a data rate of about 30kbps. Accordingly, an 8-bit or 16-bit microcomputer chip driven by aclock signal having a frequency of about 10 MHz can be used in executingthe system control and the error correction. In the case where the errorcorrection related to the optical reproduction is executed by anexclusive IC and the error correction related to the magnetic recordingand reproduction is executed by the microcomputer, it is possible toomit a magnetic error correction circuit. Since it is unnecessary to adda new error correction circuit with an interleaving function in thisway, this design is advantageous in that the structure of the apparatusis simple.

FIG. 211 shows an arrangement using a method in which error correctionis performed both before and after an interleaving process. Thearrangement of FIG. 211 is similar to the arrangement of FIG. 1 and FIG.202 except for design changes indicated hereinafter.

In the arrangement of FIG. 211, magnetic record data is ECC-encoded by aReed-Solomon C2 error correction encoder 35a in an error correctingportion 35, and a C2 parity 45 is added thereto. Then, the resultantdata is processed by an interleaving portion 35b as follows.Specifically, as shown in FIG. 212(a), data in a transverse direction51a is read out along a longitudinal direction 51b so that the data isoutputted as shown in FIG. 212(b). For example, data segments A1 and A2are dispersed and separated by a dispersion length L1. Subsequently, aReed-Solomon C1 error correction encoder 35c subjects the data to errorcorrection encoding in the longitudinal direction, and a C1 parity isadded thereto. The resultant data is magnetically recorded onto arecording medium.

In the arrangement of FIG. 211, during reproduction, data demodulated byan MFM demodulator 30d is subjected by a Reed-Solomon C1 errorcorrecting portion to random error correction responsive to the C1parity. Then, the data is mapped by the RAM 36x of the de-interleavingportion 36b in FIG. 208, being subjected to address conversion reverseto that of FIGS. 212(a) and 212(b). Therefore, the data is re-arrangedinto the original data along the transverse direction before beingoutputted. In this way, a burst error is dispersed and made into randomerrors. The random errors are corrected by a Reed-Solomon C2 errorcorrecting portion 36a of FIGS. 212(a) and 212(b), and the error-freeresultant data is recovered and outputted.

Since the arrangement of FIGS. 212(a) and 212(b) executes the errorcorrection at two stages, that is, before and after the interleaving,burst errors can be effectively compensated. Although the single-stageerror correction in FIG. 202 suffices as shown by the experimental data,it is preferable to use such two-stage error correction in recording andreproducing very important data.

DESCRIPTION OF THE SECOND PREFERRED EMBODIMENT

FIG. 19 shows a recording and reproducing apparatus according to asecond embodiment of this invention which is similar to the recordingand reproducing apparatus of FIG. 1 except that a magnetic head 8a and amagnetic head circuit 31a are added thereto.

As shown in FIG. 20, a magnetic head 8 executes magnetic recording on anentire region of a magnetic recording layer 3, the magnetic recordinghaving a long recording wavelength. This process is similar to thecorresponding process in the first embodiment. Subsequently, themagnetic head 8a executes magnetic recording on a surface portion 3a,the magnetic recording having a short recording wavelength.Consequently, the surface portion 3a and a deep layer portion 3b aresubjected to the magnetic recordings of independent sub and mainchannels having a shorter wavelength and a longer wavelengthrespectively. In the case where a magnetic recording layer subjected totwo-layer recording as shown in FIG. 20 undergoes a reproducing processby use of a magnetic head for a long wavelength such as the magnetichead for modulating the magnetic field in the first embodiment,information can be reproduced from the main channel. This provided thatsummary information is recorded on the main channel while detailedinformation is recorded on the sub channel, the summary information canbe reproduced by the system of the first embodiment and thus there willbe an advantage such that the compatibility can be ensured between theapparatus of the first embodiment and the apparatus of the secondembodiment.

FIG. 21 shows a case where only a short-wavelength magnetic head 8 isprovided. In this case, a signal of the sub channel, on which a signalof the main channel is superimposed, is reproduced so that informationof both the main and sub channels can be reproduced. When the structureof FIG. 21 is applied to an apparatus exclusively for reproduction, itscost can be low.

An upper part of FIG. 22 shows a case where recording is done by amagnetic head for modulating a magnetic field, that is, a magnetic head8 for a long wavelength. As shown in the drawing, in the case where anN-pole portion is set “1” and a non-magnetized portion is set “0”,recording is done as “0” in magnetization regions 120a and 120b andrecording is done as “1” in a magnetization region 120c. Thus, a datasequence of “101” is obtained. As shown in a lower part of FIG. 22, inthe case where an N-pole portion is set “1” and a non-magnetized portionis set “0” by using a short-wavelength magnetic head 8b for vertical, adata sequence of “10110110” is obtained. In this case, 8-bit informationcan be recorded on a region 120d equal in size to a region 120a in theupper part of the drawing. When the information is reproduced from theregion 120d by the magnetic head 8, the reproduced information isdecided to be “1” since there are only N-pole portions. This is the sameas the region 120a. Thus, “1” in the data sequence 122a can bereproduced. In the case where an S-pole portion is defined as “0” and anon-magnetized portion is defined as “1” in a region 120e. 8-bitinformation, that is, a data sequence of “01001010”, can be recorded.When this information is reproduced by the magnetic head 8, thereproduced information is decided to be “0” since there are only S-poleportions. This is one bit, and a signal equal in polarity to the signalon the region 120b is reproduced with a slightly-smaller amplitude.Thus, as shown in FIG. 22, the short-wavelength magnetic head 8b recordsand reproduces the signal of the data sequence 122a of the main channelD1 and the signal of the data sequence 122 of the sub channel D2, whilethe magnetic head 8 for modulating the magnetic field reproduces thedata sequence 122a of the main channel D1. Accordingly, there will be anadvantage such that the compatibility can be ensured. The gap of themagnetic head 8 for modulating the magnetic field is preferably equal to0.2 to 2 μm.

DESCRIPTION OF THE THIRD PREFERRED EMBODIMENT

FIG. 23 shows a recording portion of a third embodiment of thisinvention. In the third embodiment, a reflecting film 84 provided withpits as shown in FIG. 9 was formed on a transparent substrate 5 for arecording medium 2, and a magnetic recording film 3 was provided. Thisprocess is similar to the corresponding process in the first embodimentexcept that a film of Co-ferrite was formed by plasma CVD or others.This material has a transparency, and it has a high light transmissivitywhen its thickness is small.

As shown in FIG. 23, light emitted from an optical head 6 is focusedinto a spot 66 on the recording medium from the back side thereof. Theoptical head 6 has a lens 54 which is connected to a slider 41 by aconnecting portion 150. The connection portion 150 has a spring effect.The slider 41 is made of transparent material. A magnetic head 8 isembedded into the slider 41. Thus, the optical head 6 reads the pits inthe reflecting film 84 from the back side, and thereby tracking andfocusing are controlled. Thus the slider 41 connected thereto issubjected to tracking control so that the optical head 6 can follow agiven optical track. A positional error between the lens 54 and theslider 41 is caused by only the spring effect of the connecting portion150, and the slider 41 is controlled with an accuracy of a micron order.Upward and downward head movement is done together with the focusingcontrol, and the movement is controlled with an accuracy of an order ofseveral microns to several tens of microns.

Segments of information are sequentially recorded on the magneticrecording layer 3 by magnetic recording. In this embodiment, sinceoptical tracking is enabled, there is a remarkable advantage such that atrack pitch of several microns can be realized. Since the slider 41 andthe magnetic head 8 are moved upward and downward according to thefocusing control, a given track can be correctly followed by themagnetic head 8 even when the surface accuracy of the substrate 5 of therecording medium 2 is low. Thus, it is possible to use a substratehaving a low surface accuracy. Accordingly, there is a advantage suchthat an inexpensive substrate, for example, a plastic substrate or anon-polished glass substrate, can be used which is much cheaper than apolished glass substrate.

FIG. 23 shows the case where the optical head 6 executes the informationreproduction on the recording medium 2 from the back side thereof. Theinformation reproduction can also be done on the recording medium 2 by amechanism such as a conventional optical disk player from the upper sidethereof, and thus there is an advantage such that the compatibility canbe ensured. In addition, there is a notable advantage such that a memorycapacity greater than that in a conventional case by one or more orderscan be realized by using the optical tracking.

DESCRIPTION OF THE FOURTH PREFERRED EMBODIMENT

FIG. 24 shows a recording and reproducing apparatus according to afourth embodiment of this invention which is similar to the recordingand reproducing apparatus of FIG. 1 except for design changes indicatedhereinafter. In the first embodiment; the magnetic head 8 uses themagneto-optical recording head for modulating the magnetic field as itis, and the vertical recording is done as shown in FIG. 3. On the otherhand, in the fourth embodiment, as shown in FIG. 25, a magnetic head 8has the function of horizontal magnetic recording and also the functionof magneto-optical recording magnetic-field modulation, and the magnetichead 8 is used to execute horizontal recording on a magnetic recordinglayer 3 of a recording medium 2.

An equivalent head gap of the magnetic-field modulating head in thefirst embodiment, for example, a head for an MD (a minidisk), isgenerally 100 μm or greater, so that the recording wavelength λ isseveral hundreds of μm. In this case, a counter magnetic field isgenerated and thus a magnetism effectively used for actual recording isreduced, so that the level of a reproduced output is lowered. The firstembodiment has a remarkable advantage such that a cost increase isprevented since a change of the structure is unnecessary, but the levelof a reproduced output tends to be low.

In the case where a high level of a reproduced output is required withrespect to long-wavelength recording, horizontal recording ispreferable. In order to realize the horizontal recording, the fourthembodiment is modified from the first embodiment in a manner such thatthe structure of a magnetic head is changed and a recording system ischanged from vertical recording to horizontal recording.

As shown in FIG. 25, the magnetic head 8 of the fourth embodiment has amain magnetic pole 8a, a sub magnetic pole 8b, a head gap 8c, and awinding 40. The main magnetic pole 8a has the function of a magnetichead for modulating a magnetic field. The sub magnetic pole 8b serves toform a closed magnetic circuit. The head gap 8c has a gap length L.During horizontal recording, the magnetic head 8 is regarded as a ringhead having a gap length L. The magnetic head 8 is designed so as toapply a uniform magnetic field to an optical recording layer 4 duringthe magneto-optical, recording of the magnetic field modulation type.

In the case of a magnetic mode of operation which is shown in FIG. 25,light emitted from the optical head 6 is focused into a spot 66 on theoptical recording layer 4, and the optical head 6 reads out trackinformation or address information therefrom. The optical head 6 issubjected to tracking control so that a given, optical track can bescanned. Thus, the magnetic head 8 connected to the optical head 6travels on a given magnetic track. As shown in FIG. 25, while therecording medium 2 is moved in a direction 51, horizontal magneticsignals 61 are sequentially recorded in the magnetic recording layer 3in accordance with an electric information signal fed from a magneticrecording block 9. When the gap length is denoted by L and the recordingwavelength is denoted by λ, there is a relation as λ>2L. Thus, as thegap length L is decreased, a recording capacity is greater. In the casewhere the gap length L is reduced, a region subjected to a uniformmagnetic field is narrowed during the generation of a modulationmagnetic field for the magneto-optical recording. Thus, in this case,the recordable region with respect to the light spot 66 provided by theoptical head 6 is narrowed and it is necessary to increase the accuracyof the sizes of the recording medium and the tracking mechanism, andthus the cost tends to be increased.

In the case of the execution of the magneto-optical recording as shownin FIG. 26, a spot 66 of laser light from the optical head 6 heats thecorresponding point of the optical recording layer 4 to a temperatureequal to or higher than a Curie temperature thereof. The point of theoptical recording layer 4 which is exposed to the light spot 66 ismagnetized in accordance With a modulation magnetic field generated bythe magnetic head 8, and segments of an information signal 52 aresequentially recorded on the optical recording layer 4. The positionalrelation between the optical head 6 and the magnetic head 8 is affectedby the accuracy of the size of the tracking mechanism which includes ahead base 19. In the case of an MD, to lower the cost, the standard ofthe size accuracy is lenient. Thus, when worst conditions areconsidered, there is a chance that the positional relation between theoptical head 6 and the magnetic head 8 is greatly out of order.Accordingly, it is preferable that the area of a region 8e exposed to auniform magnetic field is as large as possible.

As shown in FIG. 26, the main magnetic pole portion 8a of the magnetichead 8 is formed with a tapered condensing section 8d, and therebyright-hand magnetic fluxes 85a and 85b are condensed so that a magneticfield is strengthened. Thus, the magnetic fluxes 85a and 85b are madeequivalent to magnetic fluxes 85c, 85d, 85e, and 85f, and there is anadvantage such that the region 8e exposed to a uniform magnetic field isenlarged. In this way, even when the relative position between theoptical head 6 and the magnetic head 8 moves out of the correct positionso that the relative position between the light spot 66 and the magnetichead 8 also moves out of the correct position, an optimal modulationmagnetic field is applied to the optical recording layer 4 provided thatthe light spot 66 exists within the region 8e exposed to the uniformmagnetic field. Accordingly, the magneto-optical recording is surely,executed, and an error rate is prevented from being worse.

As shown in FIG. 31, magnetic fluxes of the magnetically recorded signal61 on the magnetic recording layer 3 are formed as magnetic fluxes 86a,86b, 86c, and 86d. During the magneto-optical recording, the portion ofthe magneto-optical recording material which is heated by the light spot66 to a temperature equal to or higher than the Curie temperaturethereof is subjected to the magnetic field of the magnetic flux 86a bythe magnetically recorded signal 61 and also the modulation magneticfield from the magnetic head 8. When the magnetic field of the magneticflux 86a is stronger than the modulation magnetic field from themagnetic head 8, the magneto-optical recording responsive to themodulation magnetic field can not be correctly done. Thus, it isnecessary to limit the magnitude of the magnetic flux 86a to a givenlevel or less. Accordingly, an interference layer 81 having a thicknessd is provided between the magnetic recording layer 3 and the opticalrecording layer 4 to reduce the adverse influence, of the magnetic flux86a. When the shortest recording wavelength is denoted by λ, thestrength of the magnetic flux 66 at the optical recording layer 4 isattenuated by about 54.6×d/λ. In the case of a recording medium, it canbe thought that various recording wavelengths λ are used. It is generalthat the shortest recording wavelength is equal to 0.5 μm. In this case,when the thickness d is 0.5 μm, attenuation of about 60 dB is obtainedso that the adverse influence of the magnetically recorded signal 61hardly occurs.

As previously described, by using an interference film of a thickness of0.5 μm or greater between the magnetic recording layer 3 and the opticalrecording layer 4, there is provided an advantage such that themagnetically recorded signal hardly affects the magneto-opticalrecording. The interference film is preferably made of non-magneticmaterial or magnetic material having a weak coercive force.

In the case where the magneto-optical recording and the magneticrecording are done by using a magneto-optical recording medium, amodulation magnetic field is prevented from injuring a recorded magneticsignal provided that the modulation magnetic field for themagneto-optical recording is sufficiently weaker than the coercive forceof magnetic material for a magnetic recording layer. When a ring-typehead is used as in the previously-mentioned case, a strong magneticfield occurs in a head gap portion. Thus, even if the modulationmagnetic field is weak, there is a chance that the modulation magneticfield adversely affects a recorded magnetic signal and thus an errorrate is increased. This problem is resolved as follows. In the case ofrecording on a magneto-optical recording medium, as shown in FIG. 27,before the optical head 6 records a main information signal on theoptical recording layer, an information signal magnetically recorded ona magnetic track 67g at the opposite side of an optical track 65g to bescanned is transferred to the memory 34 in the recording and reproducingapparatus or written on the optical recording layer to be saved. Thesaving prevents a problem even when recorded data in the magneticrecording layer are damaged by the modulation magnetic field during themagneto-optical recording.

A system controller 10 operates in accordance with a program stored inan internal ROM. FIG. 28 is a flowchart of this program. The program ofFIG. 28 is divided into six large blocks. A decision block 201 decidesthe character of a disk. In the case of a ROM disk, anexclusive-reproduction block 204 is used. In the case of reproduction onan optical RAM disk, a reproduction block 202 is executed and sometimesa reproduction/transfer block 203 is executed. In the case of recordingon an optical RAM disk, a recording block 205 is used and sometimes arecording/transfer block 206 is used. In the presence of a free time,only transfer is executed by a transfer block 207.

The program of FIG. 28 will now be described in more detail. In thedecision block 201, a step 220 places a recording medium 2, that is, adisk, into a correct position or an operable position. A step 221decides the type of the disk by detecting a click on a disk cassettesuch as shown in FIG. 16. There are various types such as a ROM, a RAM,an magneto-optical recording medium, an optical recording preventiondisk, and a magnetic recording prevention disk. A subsequent step 222moves the optical head 6 to a position aligned with an inner mostoptical track 65a and an innermost magnetic track 67a. A step 223 readsout magnetic information data and optical information data from a TOCregion of the recording medium. In the case of a music disk, data isinputted which represents a music number at the end of previousoperation. In the case of a game disk, data is inputted which representsa stage number at the previous end of the game. As shown in FIG. 16,when the user desires continuation in response to the inputted data,conditions at the end of previous operation are retrieved. A step 224reads out an un-transfer flag from the magnetic TOC region. Theun-transfer flag being “1” represents that magnetic data which is nottransferred to an optical data section remains. The un-transfer flagbeing “0” represents it does not remain. A step 225 decides whether thedisk is a magneto-optical disk or a ROM disk. When the disk is a ROMdisk, an advance toward a step 238 is done. When the disk is amagneto-optical disk an advance toward a step 226 is done. When the step238 detects the presence of a reproducing instruction, a step 239reproduces an optically recorded signal and a magnetically recordedsignal. When the operation ends at a step 240, a step 241 writesinformation into, the TOC region of the magnetic track. The writteninformation represents various changes occurring during thereproduction, for example, changes in the music reproduction order andthe music number at the end of the operation. After writing theinformation is completed, a step 242 ejects the disk.

As previously described, when the disk is a magneto-optical disk, anadvance toward a step 226 is done. In the presence of a reproducinginstruction, an advance to a step 227 is done. Otherwise, an advance toa step 243 is done. The step 227 executes reproducing a main recordedsignal on an optical recording surface at a speed higher than a normalreproduction speed, and sequentially stores the reproduced informationinto a memory. In the case of a music signal, an amount of data whichcorresponds to several seconds can be stored. Thus, even if thereproduction is interrupted, reproduced music can be continued. When astep 228 detects that the memory is completely filled with thereproduced information, a step 229 is executed. When the step 229decides that an un-transfer flag is “1”, the reproduction of the mainrecorded signal is interrupted and an advance to a step 230 in thereproduction/transfer block 203 is done. A check is made as to whetheror not all of a sub recorded signal on a magnetic recording surface hasbeen reproduced. When the result of the check is Yes, an advance to astep 234 is done. Otherwise, an advance to a step 231 is done, and thesub recorded signal on the magnetic recording surface is reproduced andthe reproduced information is stored into the memory. A step 232 checkswhether or not outputting the stored main recorded signal such as themusic signal is still possible. When the result of the check is No, areturn to the step 227 is done and reproducing and storing the mainrecorded information are executed. In the case where the result of thecheck is Yes, at the moment at which the sub recorded signal reaches apreset memory amount in a step 233, the step 234 again checks whether ornot storing and reproducing the main recorded signal can be done. Whenthe result of the check is Yes, a step 235 transfers and writes the subrecorded signal from the memory into a transfer region on the opticalrecording-surface. Then, a step 236 checks whether or not transferringall the data is completed. When the result of the check is No, a returnto the step 230, is done and the transfer is continued. When the resultof the check is Yes, a step 237 changes the un-transfer flag from “1” to“0” and then a return to the step 226 is done.

In the case of recording on the optical recording layer, an advance to astep 243 in the recording block 205 is done, and a check is given withrespect to a recording instruction. When the result of the check is Yes,a step 244 executes storing the main recorded signal into the memory andthe optical recording is not executed. A step 245 checks whether, or notthe memory has a free area. When the result of the check is No, a step245a executes the optical recording of the main recorded signal and areturn to the step 243 is done. When the result of the check is Yes, anadvance to a step 246 is done. When the un-transfer flag is not “1”, areturn to the step 243 is done. Otherwise, an advance to a step 247 inthe recording/transfer block 206. The step 247 stores the main recordedsignal into the memory, and simultaneously reproduces a sub recordedsignal on a magnetic track 67g at the opposite side of an optical track65g of FIG. 27 which is planned to be subjected to the optical recordingat this time. In addition, the step 247 stores the reproduced subrecorded signal into the memory. A step 248 checks whether, or not thememory has a free area. When the result of the check is Yes, a step 248atransfers and writes the sub recorded signal into the optical recordinglayer. When the result of the check is No, a return to the step 245a isdone and the optical recording is executed. A step 249 checks whether ornot transferring all the data has been completed. When the result of thecheck is Yes, a step 250 changes the un-transfer flag from “1” to “0”and then a return to the step 243 is done. Otherwise, nothing is doneand a return to the step 243 is done.

The step 243 checks whether or not a recording instruction is present.When the result of the check is No, an advance to a step 251 in thetransfer block 207 is done. Here, recording and also reproducing themain recorded signal are unnecessary, and thus only the transfer of asub recorded signal from a magnetic data surface to an optical datasurface is executed. The step 251 executes reproducing the sub recordedinformation and storing the reproduced sub recorded information into thememory. A step 252 executes the transfer of the sub recorded signal fromthe memory to the optical recording layer. A step 253 checks whether ornot transferring all the data has been completed. When the result of thecheck is No, a return to the step 251 is done so that the transfer iscontinued. Otherwise, a step 254 changes the un-transfer flag from “1”to “0”, and then a step 255 checks whether or not all the operation hasbeen ended. When the result of the check is No, a return to the firststep 226 is done. Otherwise, an advance to a step 256 is done, and theinformation which has been changed by this work and other informationsuch as information representing that the un-transfer flag is “0” aremagnetically recorded on the TOC region of a magnetic track. Then, astep 257 ejects the disk, and the work regarding this disk is ended.

It should be noted that the step 256 may again write all the subrecorded signal into the magnetic recording layer from the memory toreturn the magnetic recording layer to the conditions which occur beforethe execution of the optical recording.

As previously described, only the data in the magnetic track among thedata on the magnetic recording surface, which might be damaged by amodulation magnetic field during the optical recording, is transferredand saved into the memory or the optical recording surface. Thus, thereis an advantage such that a damage to the data on the magnetic recordingsurface can be substantially prevented.

Optical recording may be done by recording saved data on a magnetictrack again and retrieving the saved data after the work of opticalrecording. In this case, there is an advantage such that data on amagnetic recording surface is retrieved upon the ejection of a disk.

The design of FIG. 28 uses a method where data on a magnetic recordingsurface, which might be damaged, is transferred to an optical recordingsurface before magneto-optical recording is done. On the other hand, adesign of FIG. 29 uses a method where data transfer to an opticalrecording surface is not executed. A decision block 201, a reproductionblock 202, and an exclusive reproduction block 204 of FIG. 29 aresimilar to those of FIG. 28, and a description thereof will be omitted.Since the data transfer is not executed, it is unnecessary to provide areproduction/transfer block 203, a recording/transfer block 206, and atransfer block 207. A recording block 205 of FIG. 29 differs from thatof FIG. 28, and a detailed description thereof will be givenhereinafter.

A step 226 in the reproduction block 202 checks whether or not areproducing instruction is present. When the result of the check is No,an advance to a step 264 is done. Otherwise, an advance to a step 260 isdone. The step 260 manages a processed optical track in unit of amagnetic track, and a calculation is given of a magnetic track at theopposite side of an optical track which may be damaged bymagneto-optical recording. In addition, a check is made as to whether ornot the present track is the same as the track subjected to previoussaving. When the result of the check is Yes, a step 263 executesmagneto-optical recording on the optical track. Otherwise, a step 261writes the saved data into the previous magnetic track, and thereby thedata on the previous magnetic track can be fully retrieved. Next, a step262 reads out data from the magnetic track which may be damaged at thistime, and saves the readout data into the memory. Then, a step 263executes recording on the optical track, and a return to a step 243 isdone. When the result of a check by the step 243 is No, a step 261aretrieves the previous conditions of the magnetic track. Thereafter, astep 264 in an end block 206A checks whether or not the operation isended. When the result of the check is No, a return to the step 226 isdone. Otherwise, a step 265 executes magnetically recording informationwhich has been changed during the interval from the placement of thedisk to the end, for example, information of the ending music number.Then, a step 266 ejects the disk. In this way, the work is ended. When anext disk is placed into an apparatus, the work is started again at thestep 220.

In the design of FIG. 28, all the magnetic data is transferred to theoptical recording layer to cope with a damage to the magnetic data bythe magneto-optical recording. On the other hand, in the design of FIG.29, magnetic data is managed in unit of a magnetic track, and reading isgiven on only magnetic data from a magnetic track which may be damagedby the magneto-optical recording. The readout data is stored into thememory. When the magnetic track is damaged by the magneto-opticalrecording and optical recording on another magnetic track is done, theformer magnetic track is completely retrieved. Thereby, a memorycapacity which corresponds to one magnetic track to three magnetictracks suffices, and the capacity of the memory can be relatively small.As made clear from FIG. 29, the design of this drawing has an advantagesuch that a simple process can protect magnetic data from being damagedby the magneto-optical recording.

As shown in FIG. 30(a) and FIG. 30(b), a reproducing process can begiven on a magneto-optical disk and a CD by using a same mechanism. Inthe case of a CD, since a protective cartridge is absent, the CD tendsto be affected by an external magnetic field. By setting a magneticcoercive force in a magnetic recording layer 3 of a CD to 1,000 to 3,000Oe and thus making it much stronger than that in a magnetic recordinglayer of a magneto-optical recording medium, there is provided anadvantage such that magnetic data can be prevented from being damaged byan external magnetic field. In the case of a magneto-optical disk, if amagnetic coercive force is increased to a level near the magnitude of amodulation magnetic field, the magnetic coercive force can provide anadverse influence. Thus, the magnetic coercive force is set to 1,000 Oeor less.

DESCRIPTION OF THE FIFTH PREFERRED EMBODIMENT

FIG. 32 shows a recording and reproducing apparatus according to a fifthembodiment of this invention which is similar in basic operation to theapparatus of FIG. 1 and FIG. 24 related to the first embodiment and thefourth embodiment. The fifth embodiment differs from the firstembodiment in the following points.

As shown in FIG. 33, the fifth embodiment includes two windings, thatis, a magnetic-field modulating winding 40a and a magnetically recordingwinding 40b. With reference to FIG. 32, during the magnetic recording orreproduction, a magnetic head circuit 31 feeds or receives a current toor from the magnetic recording winding 40b to execute the magneticrecording or reproduction.

During the execution of the magneto-optically recording of themagnetic-field modulation type, a magnetic-field modulating circuit 37ain an optical recording circuit 37 feeds a modulation signal to themagnetic-field modulating winding 40a to realize the magneto-opticalrecording.

With reference to FIG. 33, a description will now be given of operationof the recording and reproducing apparatus which occurs during themagnetic recording and reproduction. A recording current fed from themagnetic head circuit 31 flows in a direction denoted by the arrow inthe drawing. Thus, a magnetic closed circuit of magnetic fluxes 86c,86a, and 86b is formed, and time segments of an information signal 61are sequentially recorded on a magnetic recording layer 3. The magneticrecording is done in a horizontal direction. In this case, no current isbasically fed to the magnetic-field modulating winding 40a. In thisstructure, a closed magnetic circuit including a gap 8c is formed, andoptimal designing of a reproduction sensitivity is enabled.

With reference to FIG. 34, a description will now be given of operationof the recording and reproducing apparatus which occurs during themagneto-optical recording. The magnetic-field modulating winding 40a iswound on a main magnetic pole 8a and a sub magnetic pole 8b of a yoke inequal directions. Thus, when a modulating current flows from themagnetic-field modulating circuit 37a in a direction 51a, downwardmagnetic fluxes 85a, 85b, 85c, and 85d occur. Magneto-opticallyrecording material in a point of an optical recording layer 4, which isexposed to a light spot 66 and which is heated to a Curie temperaturethereof or higher, undergoes magnetization inversion in response to themagnetic field so that an information signal 52 is recorded. In thiscase, the strength of the magnetic field at the light spot 66 isgenerally set to 50-150 Oe in a region 8e exposed to a uniform magneticfield. As shown in FIG. 25, it is preferable to provide an interferencelayer 81 to prevent the magneto-optical recording material from beingsubjected to magnetization inversion in response to an informationsignal 61. It is good to set the thickness d of the interference layer81 as λ>d.

The structure of FIG. 34 has an advantage such that the region 8eexposed to the uniform magnetic field can be wide. In addition, sincerecording heads can be independently designed with respect to the twowindings, there is provided an advantage such that optimalmagnetic-field modulating characteristics, optimal magnetic recordingcharacteristics, and optimal magnetic reproducing characteristics can beattained. Since the head gap 8c of FIG. 33 can be small, it is possibleto shorten the wavelength which occurs during the magnetic recording.Since optimal designing of the formation of a closed magnetic field isenabled, the reproduction sensitivity can be enhanced. As shown in FIG.34, during the magnetic-field modulation, the magnetic flux 85a of themain magnetic pole 8a and the magnetic flux 85d of the sub magnetic pole8b extend in the equal directions, so that a strong magnetic field doesnot occur in the gap 8c but only a weak magnetic field corresponding tothe modulation magnetic field occurs. Since a magnetic coercive force inthe magnetic recording, layer 3 is 800-1,500 Oe and is adequatelystronger than the modulation magnetic field and since there is an easilymagnetized axis in a horizontal direction there is provided an advantagesuch that a magnetically recorded signal 61 is prevented from beingdamaged by the modulation magnetic field. Thus, by setting the magneticcoercive force Hc of the magnetic recording layer 3 stronger than therecording magnetic field Hmax applied to the magneto-optical recordingmaterial, a damage to the data is prevented. In the case of theprovision of an allowance corresponding to double, it is good tomaintain a relation as Hc<2Hmax. In addition, it is good to fabricate arecording medium 2 shown in FIG. 8. As shown in FIG. 35, in a magnetichead 8, windings 40a and 40b may be separately wound on a main magneticpole 8a and a sub magnetic pole 8b respectively. In this case, duringthe magnetic-field modulation, a modulating current is also driventhrough the magnetic recording winding 40b in a direction 51b by using amagnetic head circuit 31, and thereby a magnetic flux 85d occurs whichextends in a direction equal to the directions of the magnetic fluxes85c, 85b, and 85a. Thus, it is possible to obtain an advantage similarto the advantage of the design of FIG. 34.

As shown in FIG. 36, a tap 40c may be provided to a single winding toform two divided sub windings having, three terminals. During themagnetic recording, the tap 40c and a tap 40e are used. During themagneto-optical recording, as shown in FIG. 37, a tap 40d and a gap 40eare used to generate a modulating magnetic field for the magneto-opticalrecording. In this way, three taps enable the formation of a magnetichead, and thus there is an advantage such that wiring is simple.

DESCRIPTION OF THE SIXTH PREFERRED EMBODIMENT

FIG. 38 shows a recording and reproducing apparatus according to a sixthembodiment of this invention which is similar in basic operation to theapparatus of FIG. 1. FIG. 24, and FIG. 32 related to the firstembodiment, the fourth embodiment, and the fifth embodiment. The sixthembodiment differs from the fifth embodiment in the following points.

As shown in FIG. 38, a magnetic head 8 is formed with two gaps 8c and8e. In addition, two windings 40b and 40f are connected to a magnetichead circuit 31, and one is used for recording and the other is used forerasing. Thus, erasing and recording can be done by a single head.

As shown in FIG. 39, the magnetic head 8 includes a first sub magneticpole 8b and a second sub magnetic pole 8d. Before the magnetic recordingis done by a magnetically recording winding 40b as described withreference to FIG. 33, the magnetic head circuit 31 feeds an erasingcurrent via the second sub magnetic pole 8d. Thus, before the recording,erasing magnetization from a magnetic recording layer 3 can be done bythe gap 8e. Therefore, ideal magnetic recording can be done by using thegap 8c, and there is provided an advantage such that C/N and S/N areenhanced while an error rate is reduced.

As shown in FIG. 41, guard bands 67f and 67g are provided along oppositesides of a recording track 67. First, the gap 8e of the second submagnetic pole 8d executes an erasing process with a width of an erasedregion 210. As a result, an entire region of the recording track 67 andportions of the guard bands 67f and 67g are subjected to the erasingprocess. Thus, even if the magnetic head 8 has an tracking error, thegap 8c will not move out of the erased region 210 and the gap 8c canexecute good recording.

As shown in FIG. 42, an erasing gap may be divided into two gaps 8e and8h. In this case, a recording medium 2 is driven in a direction 51, andthe magnetic recording is done by a gap 8c having a width greater thanthe width of a recording track 67 so that recording on portions of guardbands 67f and 67g is executed in an overlapped manner. Magnetization iserased from the overlapped portions by two erased regions 210a and 210b.Therefore, guard bands 67f and 67g are fully maintained. As a result,there is an advantage such that crosstalk between recording tracks isreduced and an error rate is lowered.

With reference to FIG. 40, a description will now be given of the casewhere magnetic-field modulation for magneto-optical recording is done byusing the magnetic head 8. The magnetic-field modulating winding 40a iswound on the main magnetic pole 8a, the first sub magnetic pole 8b, andthe second sub magnetic pole 8d so that magnetic fluxes 85a, 85b, 85c,85d, and 85e uniformly occur in the respective magnetic poles. Thus,there is an advantage such that a wide region 8e exposed to a uniformmagnetic field can be provided. In addition, even if an accuracy oftrack positions is low, a light spot 66 can be prevented from being outof an optical recording track 65.

FIG. 43 shows a magnetic head 8 having a modified winding. As shown inthe drawing, a magnetic-field modulating winding 40d is extended and isused in common to a magnetic recording winding, and a central tap 40c isprovided. Magnetic recording can be executed by using the tap 40c and atap 40e. As shown in FIG. 44, currents are driven into the tap 40d andthe tap 40e in directions 51a and 51b respectively while a current isdriven into a tap 40f in a direction 51c, and thereby magnetic fluxes85a, 85b, 85c, 85d, and 85e in equal directions occur so that a uniformmodulation magnetic field results. In this case, there is an advantagesuch that the number of taps is reduced by one and the structure issimplified.

As previously described, according to the sixth embodiment, a singlehead can be used as an erasing head, a magnetic recording head, and amagnetic-field modulating head for the magneto-optical recording.

DESCRIPTION OF THE SEVENTH PREFERRED EMBODIMENT

A seventh embodiment of this invention relates to a disk cassettecontaining a recording medium. With reference to FIG. 45(a), a diskcassette 42 has a movable shutter 301 which can cover an opening 302 fora head and holes 303a, 303b, and 303c for a liner. As shown in FIG.45(b), the shutter 301 is opened to unblock the opening 302 and also theholes 303a, 303b, and 303c in accordance with the insertion of the diskcassette 42 into a body of a recording and reproducing apparatus.

As shown in FIGS. 46(a) and 46(b), a single rectangular opening 303 fora liner may be provided.

As shown in FIGS. 47(a) and 47(b) and FIGS. 48(a) and 48(b), an openingfor a liner may be provided in a direction opposite to an opening 302for a head. In this case, as shown in FIGS. 49(a), 49(b), and 49(c), aliner 304 except a movable portion 305a is fixed to a disk cassette 42by a liner support portion 305 and liner support fixing portions 306a,306b, 306c, and 306d. The liner support portion 305 is made of a leafspring or a plastic sheet. As shown in FIG. 49(c), a cassette half isformed with a groove 307 for a liner. The liner movable portion 305a isaccommodated in the groove 307, and is held by an auxiliary linersupport portion 305b. The liner 304 is held in a flat state by thereturn spring force of the liner support portion 305 as long as anexternal force is not applied thereto. The liner 304 being in this stateseparates from a recording layer at a surface of a recording medium 2.Thus, it is possible to prevent wear of the recording layer 3.

When an external force is applied in a direction toward the interior ofthe disk cassette 42 by a liner pin 310 through the opening 303, theliner support portion 305 and the liner 304 are pressed against thesurface of the recording medium 2.

Another disk cassette will now be described. As shown in FIGS. 50(a),50(b), and 50(c), a leaf spring of a liner support portion 305 ispreviously deformed toward the upper surface of a disk cassette 42.Thereby, as shown in FIG. 50(d), when the liner support portion 305 isfixed to the disk cassette 42, the liner support portion 305continuously abuts against an upper cassette half 42a. Thus, as long asthe liner support portion 305 is not depressed, by a liner pin 310, aliner 304 and a recording medium 2 remain out of contact with eachother. According to this design, it is possible to omit the auxiliaryliner support portion 305b.

A description will now be given of a way of moving the liner and thedisk into and out of contact with each other by operating the liner pin310. FIG. 51 shows conditions where the liner pin 310 is raised along adirection 51a in a liner pin guide 311, and thus the liner 304 and therecording layer 3 of the recording medium 2 are out of contact with eachother. Therefore, the recording medium 2 receives a weak frictionalforce and can be rotated by a weak drive force.

As shown in FIG. 52, when the liner pin 310 is moved downward by anexternal force in a direction 51a, the liner 304 is pressed against themagnetic recording layer 3 of the recording medium 2 via the linersupport portion 305. As the recording medium 2 is moved or rotated in adirection 51, dust is removed from the surface of the magnetic recordinglayer 3 by the liner 304. The liner 304 is made of, for example, cloth.Thus, in the case where the magnetic recording, the magneticreproduction, or the magnetic-field modulation for the magneto-opticalrecording is executed by a recording head 8 in the head opening 301 ofFIGS. 46(a) and 46(b), there is provided an advantage such that an errorrate is remarkably reduced. The material of the liner 304 may be thesame as the material of a liner for a conventional floppy disk. As shownin FIG. 45(a), the liner pin 310 is located above the portion of themagnetic recording layer 3 which precedes the magnetic head 8 withrespect to the rotation of the recording medium 2 in the direction 51,and thus there is an advantage such that the cleaning effect isenhanced.

In the case where the liner control method of this invention is appliedto a disk cassette 42 for a contact-type magneto-optical recordingmedium having no magnetic recording layer 3, dust is removed and thusthere is provided an advantage such that an error rate is improvedduring the magneto-optical recording.

As shown in FIG. 53(b), the control of the liner pin 310 is designed sothat the liner pin 310 can be moved together with the magnetic head 8.When the magnetic head 8 falls into a contact state, the liner 304 issurely moved into, contact with the recording medium 2. Thus, a singleactuator can be used in common. In the case where the magnetic head, 8separates from the contact state, the line pin 310 is generally raisedto move the liner 304 out of contact with the recording medium 2. Asshown in FIGS. 53(a) and 53(b), in the case where the liner pin 310 andthe magnetic head 8 are moved together, the liner 304 and the recordingmedium 2 can be out of contact with each other when the identificationhole for the magnetic recording layer is absent from the cassette 42.Thus, the liner 304 less wears the surface of the magnetic recordinglayer 3. In addition, the frictional force on the recording medium 2 isreduced, and thus there is an advantage such that a weaker rotationaltorque of a drive motor suffices and the rate of consumption of electricpower is decreased. When a recording medium 2 which does not have anymagnetic recording layer is inserted into the apparatus, the magnetichead 8 and the recording medium 2 remain out of contact with each otherso that a damage to the two can be prevented as shown in FIG. 75.

In the case where the disk cassette 42 of this invention is placed intoa conventional recording and reproducing apparatus, the liner 304 doesnot contact the recording medium 2 as shown in FIG. 54(b) since theconventional apparatus does not have the liner pin 310 and the relatedelevating function as shown in FIGS. 54(a) and 54(b). Thus, therecording medium 2 can be stably rotated by the conventional apparatuswhich generally provides a weak disk drive torque. Accordingly, there isan advantage such that the compatibility between the disk cassette 42 ofthis invention and conventional disk cassettes can be maintained.

In the case where a conventional disk cassette 42 which does not havethe liner 304 and the opening 303 is placed into the recording andreproducing apparatus of this invention, the liner pin 310 is notinserted since the opening 303 is absent as shown in FIGS. 55(a) and55(b). Thus, the liner pin 310 does not contact the recording medium 2and the liner 304, and there occurs no problem. Accordingly, there is anadvantage such that the compatibility between the disk cassette 42 ofthis invention and conventional disk cassettes can be maintained. Inthis case, lubricant on the conventional recording medium is liable toadhere to the contact surface of the magnetic head 8 so that the errorrate tends to be increased. To remove this problem, a cleaning track 67xis set as shown in FIG. 56. In the case where the conventional recordingmedium 2 is placed into and ejected from the recording and reproducingapparatus of this invention and then the recording medium 2 of thisinvention is inserted thereinto, the magnetic head 8 is forced to travelon the cleaning track 67x at least once. Thereby, the lubricant istransferred from the magnetic head 8 to the cleaning track 67x. Then,the lubricant is removed from the cleaning track 67x by the liner 304which contacts the recording medium 2. In this way, the lubricant ordust is removed from the contact surface of the magnetic head 8. Thus,there is an advantage such that the error rate is small and reliablerecording and reproduction are enabled.

The liner pin 310 can be moved between an OFF position and an ONposition as shown in FIGS. 57(a) and 57(b). The mechanism for elevatingthe liner 304 has a structure such as shown in FIG. 58 and FIG. 59.

A modified liner pin 310 will now be described. As shown in FIG. 60 andFIG. 61, a liner pin 310 is of a leaf spring type. As shown in FIG. 62and FIG. 63, the liner pin 310 can be moved between an OFF position andan ON position. The liner pin 310 is driven in directions 51 and 51a byan elevating motor 21 via a pin drive lever 312, being moved between theON position and the OFF position.

In the case of use of a single rectangular opening 303, a liner pin 310can be moved between an OFF position and an ON position as shown in FIG.64 and FIG. 65. In this case, the area of contact between the liner pinand the liner attachment portion is large, and thus there is anadvantage such that dust can be surely removed.

According to a liner pin shown in FIG. 66 and FIG. 67, a liner guide 311is provided with a protective portion 314. As shown in FIG. 66, a diskcassette 42 of this invention has a recognition hole 313. In the casewhere the disk cassette 42 of this invention is inserted into arecording and reproducing apparatus, the liner pin 310 is placed in anopening 303. In the case where a conventional disk cassette 42 whichdoes not have a recognition hole 313 is inserted into the recording andreproducing apparatus, the protective portion 314 contacts an outershell of the disk cassette 42 so that the liner pin 310 remains out ofcontact with the outer shell of the disk cassette 42. Thus, there is anadvantage such that the liner pin 310 can be prevented from becomingdirty or being damaged.

DESCRIPTION OF THE EIGHTH PREFERRED EMBODIMENT

An eighth embodiment of this invention relates to a mechanism forelevating a liner pin to move a liner.

As shown in FIGS. 68(a) and 68(b), an upper surface of a disk cassettehas no opening for a liner. A back side of the disk cassette hasrecognition holes 313a, 313b, and 313c, and an opening 303 for a liner.The opening 303 extends near the recognition holes 313a, 313b, and 313c.A liner pin is inserted into the disk cassette through the opening 303from the back side, and thereby a liner is moved vertically.

FIG. 69(a) shows conditions where a liner pin 310 is in an OFF positionso that a liner 304 separates from a recording medium 2. As shown inFIG. 69(b), when a liner pin 310 is inserted into the opening 303, aliner drive member 316 is deformed by the liner pin 310 toward aright-hand side and is thus rotated counterclockwise about a pin shaft315. Thereby, a liner support portion 305 is forced downward by theliner drive member 316 so that the liner 304 is brought into contactwith the recording medium 2. As the recording medium 2 rotates, theliner 304 removes dust from the recording medium 2. The liner drivemember 316 is made of a leaf spring.

The liner has a structure such as shown in FIGS. 70(a), 70(b), and70(c). The liner structure is basically similar to the liner structurepreviously described with reference to FIGS. 49(a), 49(b), and 49(c)except for the following design changes. An edge of the liner drivemember 316 is provided with a movable portion 305a. In addition, asshown in FIG. 70(c), a groove 30a is added for accommodating the linerdrive member 316.

The drive mechanism for the liner 310 will be further described. Theliner pin 310 and a motor 17 are in a positional relation such as shownin FIG. 71. As shown in FIG. 72(a), in the case where a disk cassette 42of this invention is inserted into a recording and reproducing apparatusin a direction 51, the liner 304 is moved vertically together therewitheven if an actuator for the liner pin 310 is not provided. As shown inFIG. 72(b), in the case where a conventional disk cassette 42 having noopening 303 is inserted into the recording and reproducing apparatus,the liner pin 310 is automatically moved downward against the force of aspring 317 since the opening 303 is absent. Thus, there is an advantagesuch that the conventional disk cassette 42 is prevented from beingdamaged by the liner-pin 310. In the case of use in an apparatus such asa game machine where the frequency of access to a disk is very low, thestructure of the apparatus can be simplified since it is unnecessary toprovide an actuator for the liner pin 310.

As shown in FIGS. 73(a) and 73(b), an elevating motor 21 for a magnetichead 8 may be used also to drive a liner pin 310 via an elevator 20 anda connecting portion 318. In this design, when the magnetic head 8contacts a recording medium 2, a liner 304 always contacts the recordingmedium 2. Thus, there is an advantage such that a single actuator can beused in common for the magnetic head 8 and the liner pin 310.

FIGS. 74(a) and 74(b) show another disk cassette 42 which is basicallysimilar to the disk cassette of FIGS. 69(a) and 69(b) except that aliner drive member 316 is extended and a pin shutter 319 is added. Thus,as shown in FIG. 74(a), the pin shutter 319 is closed when a liner pin310 assumes an OFF state, and thus there is an advantage such thatexternal dust is prevented from entering the disk cassette 42. Accordingto this design, since the part near a recognition hole in the diskcassette is used, the addition of only one small hole through aconventional disk cassette suffices. Thus, there is an advantage suchthat the degree of the compatibility between the disk cassette of thisinvention and the conventional disk cassette can be enhanced. Thestructure of FIGS. 69(a) and 69(b) has an advantage such that anoccupied space in a horizontal direction can be small. Therefore, asshown in FIGS. 68(a), and 68(b), even in the case where only a smallusable space is present, an opening 303a for the liner can be provided.Thus, the degree of freedom in designing of a disk cassette is enhanced.

DESCRIPTION OF THE NINTH PREFERRED EMBODIMENT

FIG. 75 shows a disk cassette according to a ninth embodiment of thisinvention. A liner 304 and a liner attachment portion 305a areapproximately similar in structure to those in FIGS. 49(a), 49(b), and49(c). In this embodiment, as shown in FIG. 76 and FIG. 77, theliner-attachment portion 305 has a movable section 305a provided with aliner elevator 305c. As the liner elevator 305c is depressed by a linerdrive portion 316, the liner 304 is moved vertically. In the case wherea liner pin 310 assumes an OFF state, a pin shutter 319 is pressedagainst a cassette lower wall by a spring 317 so that external dust isprevented from entering the disk cassette. The liner support portion 305and the movable section 305a are pressed against a cassette upper wallby a leaf spring effect and an auxiliary liner support portion 305b.Thus, in this case, the liner 304 remains out of contact with arecording medium 2.

As shown in FIG. 77, when the liner pin 310 assumes an ON state, the pinshutter 319 forces the liner drive portion 316 to rotate clockwise abouta pin shaft 316 so that the liner drive portion 316 depresses the linerelevator 305c. Therefore, the movable section 305a of the linerattachment portion 305 is lowered so that the liner 304 is brought intocontact with the recording medium 2. As the recording medium 2 rotatesin a direction 51, the liner 304 removes dust from the surface of therecording medium 2. Thus, there is an advantage such that an error ratecan be reduced. In addition, the ninth embodiment has an advantage suchthat the structure thereof is relatively simple and the upward anddownward movement of the liner 304 can be surely executed. Since it isunnecessary to provide a groove in the disk cassette 42, there is anadvantage such that the durability of the disk cassette 42 can be high.

In the case where this embodiment is applied to the design of FIG.68(a), the liner elevating mechanism has a structure such as shown inFIGS. 78(a) and 78(b). The operation of the structure of FIGS. 78(a) and78(b) is similar to the operation of the structure of FIGS. 76 and 77.As shown in FIG. 78(a), when a liner pin 310 is in an OFF position, anopening for a liner is closed by a pin shutter 319. As shown in FIG.78(b), when the liner pin 310 assumes an ON position, a liner driveportion 316 is rotated counterclockwise and depresses a liner elevator305c. Thus, a liner attachment portion 305a and a liner 304 are loweredso that the liner 304 is brought into contact with a recording medium 2.This design has an advantage over the design of FIG. 76 such that theliner elevating mechanism occupies a smaller space.

In a design where a liner and a recording medium separate from eachother when a liner pin 310 is inserted into a disk cassette 42, there isan advantage such that the liner contacts the recording medium andprevents the recording medium from being rotated and damaged duringunuse conditions of the disk cassette 42.

DESCRIPTION OF THE TENTH PREFERRED EMBODIMENT

A recording and reproducing apparatus according to a tenth embodiment ofthis invention is similar to the recording and reproducing apparatus ofFIG. 38 except for design changes indicated later.

First, tracking will be described. As shown in FIG. 79(a), under idealconditions, a magnetic head 8 vertically aligns with an optical head 6.Thus, when the optical head accesses an optical track 65 of a givenaddress, the magnetic head 8 accesses a corresponding magnetic track 67at the opposite side of the optical track 65. In this case, a DC offsetvoltage is absent from a tracking error signal outputted by an opticalhead actuator 18. However, in fact, a variation in a spring constant ofthe optical actuator 18 and an influence of gravity cause the center ofthe optical head actuator 18 to be subjected to a positional offset ofseveral tens of μm to several hundreds of μm. In addition, duringassembly, a positional error is offered to the center of the magnetichead 8. Thus, as shown in FIG. 79(b), there occurs a positional offsetΔ1 between the center of the magnetic head 8 and the center of theoptical head actuator 18.

Even when an optical track of a given address is scanned by the opticalhead 6, there is a chance that an unrelated magnetic track is scanned bythe magnetic head 8 since a correspondence relation with a magnetictrack scanned by the magnetic head 8 is absent. Specifically, a pitch ofmagnetic tracks is generally set to 50 to 200 μm. A possible maximumoffset between the center of the optical head 6 and the magnetic head 8is equal to several hundreds of μm. Thus, under bad conditions, there isa chance that the magnetic head 8 travels on a magnetic trackneighboring a desired magnetic track and thereby wrong recording of datais executed.

To prevent such a problem, this invention adopts a method in which anoffset voltage ΔVo is provided to a tracking control signal tocompensate for the positional offset of the optical head 6 so that theoptical head 6 can accurately face the opposite side of a reference(currently-scanned) magnetic track 67. According to this design, themagnetic head 8 and the optical head 6 reliably remain in verticalalignment with each other, and the positions of the optical track 65 andthe magnetic track 67 are more highly correlated. In general, the offsetbetween the magnetic head 8 and the optical head 6 falls in a range wellcovered by a normal tracking error of several μm to several tens of μm.Even in the case where the track pitch is set to 50 μm, the magnetichead 8 can be held in good tracking conditions with respect to a desiredmagnetic track by referring to the address of a currently-scannedoptical track.

In the case where an offset voltage ΔVo is applied as shown in FIG.80(b), the offset of the optical head 6 is corrected so that themagnetic head 8 can access a desired magnetic track 67 by accessing theaddress of a currently-scanned optical track 68.

A description will now be given of calculation of a desired value of theoffset voltage ΔVo. According to the standards for a CD or an MD (amini-disk), a maximum possible offset of an optical track 65 is 200 μm.A pitch of magnetic tracks 67 corresponds to 2DD and is thus equal to200 μm in the case of a 135-TPI class. Thus, if no countermeasure isprovided, it is generally difficult to access a desired magnetic track67 by referring the address of an optical track 65 at the opposite sidethereof.

As shown in FIG. 81(a), there occurs an offset Δrn between apre-mastered optical track 65PM and a locus 65T of the optical head 6free from servo control. Here, in the case where a traverse is heldfixed and the optical head 6 is subjected to tracking servo control, theoffset of the optical track causes a tracking error signal such as shownin FIG. 81(b).

In the case where an optical track address is read out and is set as areference point when θ=0, the tracking radius is made equal to rn-Δrn bythe offset and is thus smaller than a designed tracking radius rn. Onthe other hand, in the case where an optical track address is read outand is set as a reference point when θ=180°, the tracking radius is madeequal to rn+Δrn by the offset and is thus greater than the designedtracking radius rn.

In the case where the track pitch is equal to 100-200 μm and the offsetof the optical track is equal to ±200 μm, the tracking radius tends todeviate from a desired radius if tracking servo control is absent.

As shown in FIG. 81(b), the error is minimized when θ=90° and θ=270°.Accordingly, the address of an optical track 65PM which occurs whenθ=90° or η=270° is used as a reference and the position of the center ofan optical track is determined on the basis of the reference, andthereby the radius rn of an n-th track corresponding to a setting valueis determined.

As made clear from FIG. 81(b), Δrn=0 when θ=90° and θ=270°, and astandard (reference) tracking radius rn is determined. The positions ofθ=90° and θ=270° are determined by referring to the tracking errorsignal. The address of an optical track 65 in a position on a line ofextension of these angles is used, and the optical head is subjected totracking control with respect to this optical track address 65s.Thereby, there is provided an advantage such that a standard (reference)tracking radius rn is obtained and more accurate tracking by themagnetic head is enabled. It should be noted that the optical trackaddress information is recorded on a first track of a magnetic track 67or a TOC track.

In the case of the CD or MD format, the number of pieces of addressinformation pre round of an optical track is relatively small. Thus, 360addresses can not be obtained for one degrees of 360°. As shown in FIG.86, it can be known what degrees of an angle θ a block in a given ordernumber in an address 1 corresponds to. Thereby, for example, an angularresolution in unit of degree can be obtained. Thus, by executingmanagement in unit of block, it is possible to obtain optical addressinformation of an arbitrary radius and an arbitrary angle. A tablerepresenting the correspondence between optical address information anda magnetic track number will be referred to as an address correspondencetable.

Next, a description will be given of methods of providing thecorrespondence between a magnetic track radius rm and an optical trackradius ro. A positional offset between the optical head and the magnetichead has a first component caused during manufacture and assembly and asecond component caused during operation. Positions and sizes vary partsby parts or devices to devices, and therefore the offset components cannot be uniquely determined. To maintain the compatibility, it isimportant to clarify the correspondence between the magnetic trackradius and the optical track radius.

According to a first method, a reference track is not provided on amagnetic surface of a recording medium. As shown in FIG. 79(b), duringthe formatting of a magnetic surface, a positional offset is alwayspresent between the magnetic head 8 and the optical head 6. If theformatting is done under these conditions, a track with a positionaloffset is recorded. In the case where recording and reproduction aredone on a same disk by a same drive, there is no problem since an equalpositional offset is always present.

In the case where tracking is moved to a given track, a traverse isrequired to be moved always in a same direction, for example, adirection from an inside toward an outside, in view of the fact that anactuator for the traverse has a backlash. In the case where tracking isdone again on an n-th track, an offset distance is present between themagnetic track 8 and the optical head 6 as shown in FIG. 79(b) if anoffset voltage is not applied during the tracking. Thus, when an opticaltrack same as the optical track during the recording is accessed,tracking, is done with respect to a magnetic track same as the magnetictrack during the recording so that data can be recorded and reproducedinto and from the desired magnetic track.

In the case where the recording medium which has been formatted isoperated by another drive and the drive has characteristics such that anoffset equals zero in the absence of an offset voltage as shown in FIG.82(a), an optical track and a magnetic track are out of alignment by anoffset distance as compared with the previous recording so that datawill be recorded and reproduced into and from a wrong magnetic track.

In this invention, to remove such a problem, the traverse is controlledand moved so that a reference magnetic track will be accessed first asshown in FIG. 82(a). Then, under conditions where the traverse is fixed,an offset voltage ΔV is varied so that the optical track 6 will accessan optical track 65 containing a reference address signal. As a result,the offset voltage ΔVo is determined. Thereby, the relation of thecorrespondence between the optical track and the magnetic track isprovided similar to the drive which has executed the previousformatting.

The offset voltage ΔVo is continuously applied to the actuator for theoptical track 6. Thereby, a simple structure can produce an advantagesuch that all the magnetic tracks and the optical tracks correspond toeach other with an accuracy of several μm to several tens of μm. Thus,by applying the offset voltage, it is possible to automatically access agiven magnetic track when a given optical track is accessed. Since thisadvantage is obtained by the structure having no position sensor for thelens of the optical head 6, there is an advantage such that the numberof parts can be reduced.

Next, a description will be given of a second method in which areference track is previously recorded on a magnetic recording surface.As shown in FIG. 83, during the fabrication of a disk, one magnetictrack 67 is provided which records an embedded servo track. With respectto this servo magnetic track 67s, as shown in the left-hand part of FIG.83, two magnetic tracks are recorded while the are partially overlapped.Carriers of frequencies fa and fb are recorded on the two magnetictracks respectively.

When the magnetic head 8 executes tracking on the center of the servomagnetic track during the reproduction, the magnitudes of reproducedsignals of the frequencies fa and fb are equal to each other. When thetracking deviates inwardly from the center, the output signal of thefrequency fa is greater. On the other hand, when the tracking deviatesoutwardly from the center, the output signal of the frequency fb isgreater. Thus, the traverse is moved so that the magnetic head 8 can bepositionally controlled at the center of the track.

Although the provision of the servo magnetic track causes a slightincrease in the cost of a recording medium, there is an advantage suchthat the offset voltage ΔVo can be more accurately calculated inconnection with FIG. 80(a). In addition, eccentricity information of anoptical track can be more accurately determined.

As shown in FIGS. 84(a) and 84(b), a slider 41 of the magnetic head 8 ismade of soft material such as teflon other than metal, and is formed bymolding. Thereby, there is an advantage such that the slider 41 lessdamages a magnetic recording layer 3.

As shown in FIGS. 85(a) and 85(b), when the magnetic recording is notexecuted, a slider actuator inclines the slider 41 so that the magnetichead 8 is separated from the magnetic recording layer 3 and a part of anedge of the slider 41 is brought into contact therewith.

As shown in FIG. 85(b), only when the magnetic recording is executed,the actuator inclines the slider into parallel with the magneticrecording layer so that the magnetic head 8 moves into contact with themagnetic recording layer 3. Thus, the magnetic recording is possible. Inthis case, there is an advantage such that wear of the magnetic head 8can be reduced during unexecution of magnetic recording.

DESCRIPTION OF THE ELEVENTH PREFERRED EMBODIMENT

A recording and reproducing apparatus according to an eleventhembodiment of this invention is similar to the recording and reproducingapparatus of FIG. 38 except for design changes indicated later. Theeleventh embodiment uses a non-tracking system in which tracking servocontrol is not executed on a magnetic head. The eleventh embodimentincludes a recording circuit such as shown in FIG. 87.

As shown in FIGS. 88(a) and 88(b), recording is done by using twomagnetic heads 8a and 8b, that is, an A head 8a and a B head 8b, whichhave different azimuth angles respectively. As shown in FIG. 88(b), thetrack pitch Tp of a magnetic track 67 and a head width TH have arelation as Tp<TH<2 Tp. Normally used conditions are as TH=1.5-2.0 Tp.Thus, in the case of recording on an n-th track, recording is also doneon a region of an (n+1)-th track in an overlapped manner. The overlappedportion is subjected to overwriting record during the recording on the(n+1)-th track, and therefore a recording track is formed which has awidth corresponding to the width Tp.

As shown in FIG. 89, recording is done while the two heads, that is, theA head 8a and the B head 8b, which have the different azimuth angles arechanged at θ=0° and data is overwritten thereby alternately in a spiralshape. Thus, as shown in FIG. 88, the formed track width Tp is smallerthan the head width TH. Since A tracks 67a and B tracks 67b havingdifferent azimuth angles alternate with each other, crosstalk betweentracks is absent during the reproduction. As shown in FIG. 90, guard,bands 325 are provided between neighboring track groups 326, and thusindependent recording and reproduction can be done on each of the trackgroups.

As shown in FIG. 91, data of respective tracks such as A1, B1, and A2 iscomposed of a plurality of blocks 327, and one track group is set bycombining a plurality of tracks. Guard bands 325 are provided betweentrack groups so that rewriting can be done in unit of track group. Aplurality of blocks which compose one track have a sync signal 328, anaddress 329, a parity 330, data 331, and an error detection signal 332.

Operation which occurs during the recording will now be described. Inputdata related to a designated address is fed to an input circuit 21. Inthe eleventh embodiment, data is rewritten while a track group 326 ofFIG. 91 is used as a unit. Thus, simultaneous recording is done withrespect to a plurality of tracks. Since track groups 326 are separatedby guard bands 325 as shown in FIG. 90, an adverse influence on othertrack groups, is prevented even if the recording and reproduction isdone in this unit.

In the case where the input data contains only information of a part ofa plurality of tracks, the data is insufficient and thus rewriting cannot be done on the whole of one track group 326. Accordingly, in thecase of rewriting on an n-th track group, reproduction is previouslydone on the n-th track group and all the data is stored into a buffermemory 34 of a magnetic reproducing circuit 30. The data is transmittedto the input circuit 21 as an address and data during the writing, anddata of an address equal to the input data address is replaced by theinput data. In this case, data of an address equal to the addressrelated to the input data in the buffer memory 34 may replace the inputdata.

All the data of the n-th track group 326n which should be written istransmitted from the input circuit 21 to a magnetic recording circuit 29and is modulated by a modulating circuit 334, and a separating circuit333 generates data for the A head 8a and data for the B head 8b.

As shown in FIG. 92a(a), recording A track data 328a1 is done by the Ahead 8a at t=t1. At t=t2 where a disk is rotated through 360°, recordingB track data 328b1 is done by the B head 8b.

With respect to a timing signal for the change between the A head andthe B head, a rotation signal for a disk motor 17 is used or 360°-revolution is detected by using optical address information from anoptical reproducing circuit 38. The timing signal is transmitted from adisk rotation angle detecting portion 335 to the magnetic recordingcircuit 29. An end of each track data 328 is provided with a non-signalpart 337, and a signal guard band results which prevents A track data328a and B track data 328b from overlapping.

The guard bands are present on the disk. To prevent data from beingrecorded on a track group 326 adjacent to a desired track group whilebeing passed over a guard band 325, it is necessary to accurately set arecord starting radius and a record ending radius. This invention adoptsa method in which a given optical address is used as a reference pointand a permanent absolute radius is attained.

In FIG. 87, an optical address is read out by the optical head 6 and theoptical reproducing circuit 38. The method of optical head offsetcorrection which has been described with reference to FIGS. 80(a),80(b), 82(a), and 82(b) is used to increase an accuracy. According tothe same method, an offset corrective amount is calculated, and isstored into an offset corrective quantity memory 336. The offsetcorrective amount is read out therefrom when needed. Under conditionswhere an optical head drive circuit 25 offers an offset to the opticalhead 6, a traverse actuator 23a is driven by a traverse moving circuit24a while an optical address is referred to, and a traverse is moved. Inthis way, an optical address of the optical track is referred to, andtracking can be accurately executed on a magnetic track 67. According tothe example where the recording is done by alternately using the twomagnetic heads 8a and 8b which have the different azimuth angles, therecording time tends to be long.

As shown in FIG. 88(c), the radial positions of two heads are offset byTp. In addition, A track data and B track data are simultaneouslyoutputted and transmitted from the separating circuit 333 of FIG. 87,and the traverse is fed or moved at a pitch twice Tp every round.Thereby, as shown in FIG. 92(b), recording on one track group can beexecuted in a time half the time of the above-mentioned case, and thereis an advantage such that higher-speed recording can be done.

In this way, the input data is recorded on the tracks in a spiral shape.

An example of specific designing will now be described. Even in the casewhere an offset of an optical track is ±200 μm, the offset correctingarrangement removes adverse affection of the offset and the offset fallsinto a range of a chucking offset amount which equals ±25 μm. An offsetof the rotational shaft of a motor can be limited to within a rangecorresponding to ± several μm. In this case, by setting the guard bandwidth equal to 50 μm or more, a track can be recorded which has a widthor an error within ± several μm. Thus, there is an advantage such that alarge amount of data can be recorded by the non-tracking system.

A description will now be given of traverse control which occurs in thecase of spiral recording. With reference to FIG. 89, a record startingpoint optical address 320a and a record ending point optical address320e are set as reference points. In the design of FIG. 89, it is goodthat while the disk is rotated four times, the traverse is driven at anequal pitch from the starting point to the ending point. This inventionadopts a structure in which a rotational motor rotates a screw andthereby feeds or moves the traverse. Rotation pulses from the rotationalmotor can be obtained.

As shown in FIG. 97, the traverse is moved from the starting pointoptical address 320a to the ending point optical address 320e. Duringthis period, the rotation number no of a traverse drive gear ismeasured. Since the disk is rotated four times, a system controller 10calculates a rotational speed corresponding to no/4T r.p.s. The systemcontroller 10 outputs an instruction for rotating the traverse drivegear at this speed (rotation number). The magnetic head executes datarecording with an accurate track pitch. At the end of the recording,since the magnetic head 8 lies near the ending point optical address320e, passing over the guard band and reaching the starting pointoptical address 320x of a neighboring track group can be prevented. Itis sufficient that measuring the rotational speed of the traverse drivegear is executed once each time disks are changed. This information maybe recorded on a disk. By doing traverse control while counting the linenumber of an optical track, it is possible to execute smoother and moreaccurate feed of the traverse.

FIG. 96 shows designing which uses coaxial tracks. In this case, duringthe recording on respective tracks, the traverse is moved each time sothat six points corresponding to optical addresses 320a, 320b, 320c,320d, 320e, and 320f will be accessed by the optical head. Thereby,cylindrical tracks are formed.

In the presence of a non-address region 346 which does not have anoptical address and a signal, access by referring to the optical addresscan not be executed. In this case, with respect to an optical addressregion 347, a reference radius and a disk rotational reference angle aredetermined, and the line number of an optical track is counted. Thereby,tracking can be done on a given relative position even in thenon-address region 346. Provided that a table indicating the linenumbers from reference optical address points for respective tracks ismade and is written into a magnetic TOC region 348, another drive canaccess a target magnetic track. The method of executing access byreferring to the line number is less accurate in absolute position thanthe method using the optical address, and is advantageous thereover inthat an access speed is higher. It is preferable to use the two methods.From the standpoint of high-speed access, it is good to adopt the methodwhich uses counting the line number during the reproduction. Drives areof a high density type and a normal density type. The high density typehas a head width TH which equals ½ to ⅓ of that of the normal densitytype. In addition, its track pitch equal ½ to ⅓ of the track pitch Tpoof the normal density type. In the case of non-tracking, the highdensity type can reproduce data of a normal density type but the normaldensity type can not reproduce data of a high density type.

To attain the compatibility, a compatible track is provided during therecording by using the high density type. In addition, as shown in FIG.99, the recording is done at a track pitch equal to Tpo. Thereby, thenormal density type can reproduce the recorded data. In the case wheredata on an optical surface is divided into three programs 65a, 65b, and65c as shown in FIG. 100, regions for magnetic recorded data to be savedare set in magnetic tracks 67a, 67b, and 67c extending on the surface.Thus, there is an advantage such that the displacement of the traverseis small and an access time is short.

Next, a description will be given of the reproduction principle. FIG. 93shows a reproducing section of the apparatus. The reproducing section ofFIG. 93 is approximately similar to that of FIG. 87 except for amagnetic reproducing portion 30.

First, the system controller 10 transmits a reproducing instruction anda magnetic track number accessing instruction to a traverse controller338. As in the design of FIG. 87, the magnetic head accurately accessesa target magnetic track number.

As shown in FIG. 89, tracking is done with respect to a magnetic track67 in a spiral shape, and both the output signals of the A head 8a andthe B head 8b are simultaneously inputted into the magnetic reproducingportion 30. The input signals are amplified by head amplifiers 340a and340b respectively, being subjected to demodulation by demodulators 341aand 341b and being subjected to error check by error check portions 342aand 342b to derive correct data. The correct data signals are fed to ANDcircuits 344a and 344b. Data separating portions execute the separationbetween addresses and data. Only data free from errors is transmitted tothe buffer memory 34 via the AND circuits 344a and 344b, and respectivepieces of the data are stored into respective addresses. The data isoutputted from the memory 34 in response to a reading clock signal fromthe system controller 10. When the buffer memory 34 reaches givenconditions close to overflow conditions, an overflow signal istransmitted to the system controller 10 and the system controller 10outputs an instruction to the traverse controller to reduce the traversefeed width. Alternatively, the system controller 10 may lower the speedof the motor 17 to reduce the reproduction transmission rate. As aresult, overflow is prevented.

In the case where the number of errors detected by the error checkportion 342 is large, an error signal is transmitted to the systemcontroller 10 and the system controller 10 outputs an instruction to atraverse control circuit 24a to reduce the track pitch. As a result,during the reproduction, the track pitch is reduced from the normalvalue Tp to ⅔ Tp, ½ Tp, and ⅓ Tp so that the data of an equal address isreproduced 1.5 times, double, and three times. Thus, the error rate islowered.

In the case where all data in an (n+1)-th track gathers before all datain an n-th track gathers in the buffer memory 34, there is a chance thatthe data of the n-th track can not be reproduced. In this case, thesystem controller 10 outputs a reverse direction traverse instruction tothe traverse controller to return the traverse inwardly. Then, the n-thtrack is subjected to the reproducing process. As a result, the data ofthe n-th track can be reproduced.

In this way, there is an advantage such that data can be surelyreproduced without increasing the error rate.

A description will now be given of operation of reproducing informationfrom a disk with non-tracking. As shown in FIG. 94, data is recorded ona disk, and the data includes data 345a, 345b, 345c, and 345d in an Atrack. In addition, data B1, B2, B3, and B4 in a B track are alsorecorded. When the reproduction is executed by the A head, the data inthe B track can not be reproduced due to a discrepancy in azimuth angle.

For the simplicity of description, the data in the B track will beomitted. In the case where the recorded data 345 in the A track isreproduced by the A head 8a with a track pitch Tpo equal to that duringthe recording, the loci of the track extend as track loci 349a, 349b,349c, and 349d since there is an offset in chucking with respect to thedisk. The head width TH of the A head 8a is greater than the track pitchTpo, and therefore halves of tracks on both sides are subjected to areproduction process. The B track is not subjected to a reproductionprocess. Accordingly, reproduced data free from errors, among signalsreproduced from the respective track loci, have forms such as A headreproduced data 350a, 350b, 350c, 350d, and 350e. The data aresequentially transmitted to the buffer memory 34 of FIG. 93, and arerecorded into given disk addresses. Thus, the data of the respectivetracks are fully reproduced as memory data 351a and 351b. In this way,the data of the A track with non-tracking is reproduced. The data of theB track is similarly reproduced.

As previously described, in the eleventh embodiment, the recording andreproduction can be done with a small track pitch even in the absence oftracking servo control of the magnetic head. Thus, there is an advantagesuch that a memory of a large capacity can be realized by a simplestructure. Since the traverse control is done by using the addresses onthe optical surface, a low accuracy of, feed of the traverse sufficesand a linear sensor regarding a radial direction can be omitted. In thecase of a non-tracking system, the accuracy of tracking basicallydepends on the accuracy of a bearing of a rotational motor. Generally, ahigh accuracy of the bearing of the rotational motor can be realizedwith a low cost. In the case of an MD ROM used in a cartridge, therecording wavelength can be equal to 1 μm or less so that a recordingcapacity of 2 to 5 MB can be obtained. In the case of a CD ROM, a printlayer and a protective layer are formed on a magnetic layer as will bedescribed later so that the recording wavelength is generally equal to10 μm or more. Thus, a capacity of only several tens of KB can beobtained according to the normal system. On the other hand, a capacityof several tens of KB to 1 MB can be obtained by using the non-trackingsystem. As previously described, the eleventh embodiment has anadvantage such that a large memory capacity can be realized with a lowcost while a conventional optical access mechanism for a CD, a CD ROM,an MD, or an MD ROM is used as it is.

DESCRIPTION OF THE TWELFTH PREFERRED EMBODIMENT

A recording and reproducing apparatus according to a twelfth embodimentof this invention is similar to the recording and reproducing apparatusof FIG. 87 except for design changes indicated later. The twelfthembodiment uses a recording medium in which a magnetic recording layeris formed on the back side of a ROM disk without a cartridge such as aCD ROM.

As shown in FIG. 101, the recording medium 2 includes a transparentlayer 5, an optical recording layer 4, a magnetic recording layer 3, anda print layer 43 arranged sequentially with respect to an upwarddirection. The print layer 43 has a print area 44. A label of a CD titleor letters 45 are printed on the print area 44. A protective layer 50may be provided on the print area 44. The protective layer 50 is made ofhard material having a Mohs scale of 5 or more. In the case of arecording medium such as a CD or a CD ROM which is not provided with acartridge and which has a single optical recording surface, the printarea 44 can be provided in approximately the whole of the oppositesurface. As shown in FIG. 102, in the case of an LD. LD ROM, or otherswhich have two optical recording surfaces, the print area 44 isprovided, at a central narrow region to prevent an adverse influence onthe optical reproduction.

This embodiment will be further described with respect to the case wherea CD ROM is used as the recording medium.

The recording medium is designed and fabricated as follows. As shown inFIG. 103, at a step number P=1, a substrate (a base plate) 47 isprepared which has a transparent portion 5 with pits 46. At a stepnumber P=2, an optical reflecting film 48 made of suitable material suchas aluminum is formed by vapor deposition or sputtering.

At a step number P3, suitable magnetic material such as barium ferritehaving a magnetic coercive force Hc of 1, 750 or 2, 750 is directlyapplied, and thereby a magnetic, recording layer 3 is formed. It may begood that the magnetic material is applied to a base film and the basefilm with the magnetic material is transported together with a bondinglayer to form a magnetic recording layer 3. The recording medium of thisembodiment is not protected by a cartridge. Thus, it is necessary to usemagnetic material having a high magnetic coercive force Hc to protectrecorded data from an external magnetic field generated by, for example,a magnet. It has been experimentally confirmed through a field test thata damage to recorded data is absent when an exposed recording mediumincluding a magnetic recording material having a magnetic coercive forceHc of 1,750 Oe to 2,750 Oe is used under normal industrial useconditions. As understood from FIG. 121, only a magnetic field of 1,000to 1,200 Gauss is present in a normal home. Thus, it is good that themagnetic coercive force Hc of magnetic material for the magneticrecording layer 3 is set to 1,200 Oe or more. In this embodiment byusing the material having a magnetic coercive force of 1,200 Oe or more,a damage to data is prevented during normal use. Provided that themagnetic coercive force Hc of the magnetic material is increased to2,500 Oe or more by using barium ferrite or others, the reliabilityduring the data recording can be enhanced. The material of bariumferrite is inexpensive, and is formed by a cheap application step. Inaddition, the material of barium ferrite naturally exhibits randomorientation so that a randomizing step is unnecessary. Thus, thematerial of barium ferrite is suited to a partial RAM disk of a CD ROMtype which generally requires low-cost mass production. In this case,the magnetic material, is processed into a disk. Since recording andreproduction are done along a circumferential direction, recordingcharacteristics are lowered if the magnetic material has magneticorientation in a given direction such as a magnetic card or a magnetictape. To prevent the occurrence of such orientation in a givendirection, a magnetic film is formed while a randomizer applies magneticfields in various directions before applied magnetic material hardens.As previously described, in the case of barium ferrite, there is anadvantage such that a randomizing step can be omitted. In the case of aCD or a CD ROM, the CD standards require that the title and the contentsof a medium should be printed as a label to enable a consumer tovisually identify and recognize the contents of the medium. In addition,it is preferable that a color photograph is printed to make theappearance beautiful to increase the product value. Generally, themagnetic material has a brown color or a black color of a dark tone, andtherefore direct printing thereon is difficult.

At a step number P=4, to enable color printing to conceal the dark colorof the magnetic recording layer 3, a backing or preliminary layer 43with a color such as a white color which has a high reflectivity isformed by, for example, application. The thickness of the preliminarylayer 43 is equal to several hundreds of nm to several μm. From thestandpoint of recording characteristics, a thin preliminary layer 43 isbetter. On the other hand, if the preliminary layer 43 is excessivelythin, the color of the magnetic recording layer can not be concealed.Thus, the thickness d2 of the preliminary layer 43 is required to be acertain thickness. To block the transmission of light, a thickness equalto a half of the light wavelength or more is preferable. When theshortest wavelength λ of visible light is defined as λ=0.4 μm, athickness of 0.2 μm (=λ/2) or more is preferable. Thus, the thickness d2is preferably equal to 0.2 μm or more. When d2≧0.2 μm, it is possible toattain the effect of concealing the color of the magnetic material. Fromthe standpoint of recording characteristics, it is preferable that d2≦10μm. Thus, it is desirable that 0.2 μm≦10 μm. In this case, there is anadvantage such that both color concealing characteristics and magneticrecording characteristics can be adequately obtained.

According to the results of experiments, it is discovered that athickness d2 of about 1 μm is most preferable. In the case wheremagnetic material is mixed with and added to the preliminary layer 43,there is an advantage such that an effective space loss can bedecreased.

At a step number P=5, print ink 49 made of dyes is applied so thatprinted letters 45 such as a label of FIG. 101 are indicated. Full colorprinting is possible since the printing is done on the white-colorpreliminary layer 43. As shown in FIG. 103, the print ink 49 of the dyesis applied, and the ink soaks into the preliminary layer 43 by a depthd3 so that roughness is absent from the surface of the preliminary layer43. Thus, there is an advantage such that, during the magnetic recordingand reproduction, a magnetic head touch is good and the travel of themagnetic head is prevented from removing the printed letters. In thisway, the recording medium is completed.

The magnetic recording layer 3 at the step number P=3 and the print ink49 at the step number P=5 are formed by using a gravure application stepsuch as shown in FIG. 105. Specifically, application material includingmagnetic material of barium ferrite is transferred onto an applicationmaterial transfer roll 353 from an application material bowl 352, andthe application material on the roll 353 is selectively etched into aCD-shaped etching portion 355 which remains on an intaglio drum.Unnecessary application material is removed by a scriber 356. A softtransfer roll 367 is covered with a soft resin portion 361. TheCD-shaped application material is transferred onto the soft transferroll 367 as a CD-shaped application portion 358. The application portion358 is transferred and applied to the surface of a recording medium 2such as a CD. Before the execution of a drying process, a randommagnetic field generator 362 applies a random magnetic field to therecording medium with the application material so that the applicationmaterial has random magnetic orientation. Since the transfer roll 367 issoft, accurate application to a stiff object such as a CD can be donethereby. In this way, the applications at the step numbers P=3, P=4, andP=6 are executed. The printing step P=5 may be an offset printing stepin consideration of a small film thickness.

As shown in FIG. 103, at a step number P=6, a protective layer 50 may beapplied to the recording medium. The protective layer 50 is made of ahard and transparent material having a Mohs scale of 5 or more. Theprotective layer 50 has a given thickness d4. The protective layer 50prevents the removal of the print ink, and protects the magneticrecording layer 3 from wear by an external injury or the magnetic head.Thus, there is an advantage such that the reliability of data isenhanced.

As shown in FIG. 106, a protective layer 50, a print ink 49, apreliminary layer 43, and a magnetic recording layer 3 may be appliedonto a removable film 359 by steps of P=6, 5, 4, and 3 in an orderreverse to the order of the steps previously described with reference toFIG. 103. Random magnetic orientation is provided by the random magneticfield generator 362. The resultant application film is accuratelylocated on the surface of a substrate 4 which is provided with pits 46,and transfer is executed and then fixing is executed by a thermalpressing process. Subsequently, the removable film 359 is removed. As aresult, a recording medium is completed which has a structure equal tothe structure at the step P=6 regarding FIG. 103. In the case of massproduction, the transfer method increases the throughput but decreasesthe cost. Thus, in the case of mass production of CD's, there is anadvantage such that the production efficiency is increased.

While the dyes are used during the printing in connection with FIG. 103,print ink 49 of a pigment may be used at a step number P=5 of FIG. 104.In this case, a given thickness d3 is provided. At a-step number P=6,there is provided a protective layer 50 made of transparent materialcontaining lubricant such as d4>d3. Thereby, there is an advantage suchthat roughness on the surface is decreased and a good head touch isenabled by the lubricant. The use of the pigment causes an advantagesuch that better color printing is enabled. In this case, after the stepP=5, thermal pressing may be executed to remove roughness from thesurface, and the resultant is used as a final product. In this case,since a step of making the protective layer 50 can be omitted, there isan advantage such that the number of manufacturing steps can be reducedby one.

Next, a description will now be given of a method of making a magneticshield layer. The magnetic head is present at the side of the recordingmedium 2 near the magnetic recording layer 3, while the optical head ispresent at the side of the recording medium 2 near the transparentlayer. Thus, there is a chance that electromagnetic noise leaks from theactuator for the optical head into the magnetic head and therefore theerror rate increases during the magnetic signal reproduction. As shownin FIG. 116, noise of a level close to 50 dB occurs. A magnetic shieldis provided in the recording medium 2 as a countermeasure, and therebyadverse influence of the electromagnetic noise can be reduced. As shownin FIG. 107, at a step number P=2, a magnetic layer 69 made, ofpermalloy which has a high μ (magnetic permeability) and a weak magneticcoercive force Hc is formed by a suitable process such as a sputteringprocess. The magnetic layer 69 provides a magnetic shielding effect. Inthe case where a magnetic layer 69 having a weak magnetic coercive forceis required to be formed in a short time or a thick magnetic layer 69 isrequired to be formed during the manufacture, a permalloy foil having athickness of several μm to several tens of μm may be used. A thickmagnetic layer 69 can be formed by plating. A thicker magnetic layer 69provides an enhanced magnetic shielding effect. While the opticalreflecting layer 48 is made of aluminum at the step number P=2 of FIG.103, a film of permalloy may be formed by sputtering. In this case, asingle film provides both an optical reflecting effect and a magneticshielding effect. A thick permalloy film can be formed by plating: witha low cost. Thereby, there is an advantage such that the number of stepsof forming a reflecting film and a shielding film can be halved. Inaddition to the transfer step of FIG. 106 with respect to the recordingmedium of FIG. 108, a bonding layer 60a and a magnetic layer 69 may beprovided in a sandwiched manner. The magnetic layer 69 has a high-μ filmsuch as a permalloy film having a thickness of several μm to severaltens of μm. Thus, a recording medium having a magnetic field shieldingeffect can be fabricated through the transfer step.

In a way such as previously mentioned, a recording medium is fabricatedwhich includes an optical recording layer and a magnetic recording layerwith a print surface such as shown in FIG. 101. Thus, there is anadvantage such that a label similar to a label of a conventional CDwhich meets the CD standards is provided and simultaneously a magneticrecording surface is added. As previously described with reference toFIG. 121, most of normally used magnets are ferrite magnets. In general,such magnets are not exposed. Even if a magnet is exposed, only a magnetfield of about 1,000 Oe occurs therearound. Some of magnetic necklacesare made of rare-earth material, and such magnetic necklaces are smallin size so that they hardly magnetizes the magnetic recording materialof barium ferrite. In the case of use of a magnetic recording layer madeof suitable material such as barium ferrite which has a magneticcoercive force Hc of 1,200 Oe. 1,500 Oe or more, there is an advantagesuch that data on the magnetic recording layer is prevented from beingdamaged by a normally used magnet. Furthermore, it is possible to add amagnetic shield layer made of high-μ magnetic material, electromagneticnoise from the optical head can be remarkably suppressed during themagnetic reproduction. The above-mentioned manufacturing method uses aninexpensive technique such as a gravure application technique andinexpensive materials. Thus, there is an advantage such that a RAMfunction and a print surface can be obtained without increasing the costof a partial RAM disk such as a CD or CD ROM.

A description will now be given of a method of providing the recordingmedium with an identifier, that is, an HB (hybrid) identifier, whichindicates the presence or absence of the magnetic recording layer. Inthe case of a CD, with respect to data in the optical recording layer,one block is composed of 98 frames of the EFM modulated data structureas shown in FIG. 213. According to an example, in Q bits of the subcodein the frame in the TOC area, code data in which POINT is set as “BO” isdefined as an HB identifier code data 468a. Since BO is not currentlyused, a conventional CD, a conventional CD ROM, and an HB medium with amagnetic recording layer according to this invention can bediscriminated while the compatibility thereamong can be maintained.Since the HB identifying information is stored in the TOC area, the HBrecording medium can be identified upon the first reading of the TOCarea information. Therefore, this design is advantageous in that an HBrecording medium can be identified in a short time.

As shown in FIG. 223(a), an HB recording medium 2 includes a transparentsubstrate 5 on which an aluminum vapor deposited film 4b and pits 4c areprovided. In addition, a magnetic layer 3 is provided thereon. The pitsindicate an EFM modulated signal which has a data sequence 470bcontaining subcode 470c. In the case of control bits 470e of Q bits 470din the subcode 470c, recorded HB identifier code data 468a is “0011”.According to another way, identifying code data 468a “BO” is recorded inthe POINT 470f of the TOC area. The recording medium 2 is advantageousin that the presence and absence of the magnetic recording layer can bedetected without changing the structure thereof.

DESCRIPTION OF THE THIRTEENTH PREFERRED EMBODIMENT

A recording and reproducing apparatus according to a thirteenthembodiment of this invention is similar to the recording and reproducingapparatus of FIG. 87 except for design changes indicated later. Thethirteenth embodiment uses a recording medium in which magnetic materialhaving a magnetic coercive force Hc greater than that of a normalmagnetic disk is used and, a protective layer having a thickness of 1 μmor more is provided on an uppermost portion of a magnetic recordinglayer as previously described with reference to the twelfth embodiment.In addition, the thirteenth embodiment uses a magnetic head suited tothe recording medium. Furthermore, the thirteenth embodiment is providedwith a countermeasure to the introduction of noise from an optical headthrough a magnetic field.

First, the structure of the magnetic head will be described. FIG. 110shows the recording and reproducing apparatus which uses a 3-headarrangement. Specifically, the magnetic head of FIG. 87 is divided intotwo portions and a magnetic head 8a and a reading magnetic head 8b aremade into a single unit, and a noise cancelling magnetic head 8s isadditionally provided. Reproduction can be done while recording is beingexecuted. Thus, error check is executed simultaneously.

The magnetic heads 8a and 8b will now be described with reference toFIG. 111. An optical head 6 and the magnetic heads 8a and 8b are locatedat opposite sides of the recording medium 2, and are opposed to eachother. The optical head 6 serves to access a desired track on an opticalrecording layer 4 of the recording medium 2. The magnetic heads 8a and8b move together with the optical head 6. Thus, the magnetic head 8a and8b travel on a magnetic track at the opposite side of the optical trackscanned by the optical head 6. The magnetic recording is executed by themagnetic head 8a designed for writing. The reproduction is, executed bythe magnetic head 8b.

Recording and reproducing conditions will, now be described withreferences to FIG. 113. The magnetic head 8a has a writing track widthLa and a head gap 70a with a length Lgap. Thus, a magnetic track 67ahaving a width equal to La is recorded on the magnetic recording layer3. Above the magnetic track accessed by the magnetic head 8, there is adisk cleaning portion 376 including a circular plate made of softmaterial such as felt. The disk cleaning portion 376 removes dust fromthe disk, and thus there is an advantage such that the error rate can bereduced during the reproduction. The disk cleaning portion 376 isconnected to a connection member 380 including a spring. In an OFF stateof FIG. 111, both the magnetic head 8 and the disk cleaning portion 376are out of contact with the recording medium 2. As shown in the partON-A of FIG. 111, when the magnetic head 8 is moved downward, the diskcleaning portion 376 lands on the recording medium 2. The connectionmember 380 including the spring holds the magnetic head 8 out of contactwith the recording medium 2 for a moment. Then, in an ON-B state, themagnetic head 8 softly lands on the recording medium 2. In this way, themagnetic head 8 makes a soft landing on the recording medium 2 throughtwo steps. Thus, there is an advantage such that even if the magnetichead 8 is moved upward and downward during the rotation of the recordingmedium 2, a damage to the magnetic head 8 or the recording medium 2 isprevented. As shown in FIG. 113, a portion of a magnetic track 67a whichprecedes the magnetic, head 8 is cleaned, and thus there is an advantagesuch that the error rate is reduced during the magnetic recording andreproduction. A magnetic head cleaning portion 377 is also providedwhich moves together with a magnetic head elevator 21. During theinsertion of a disk into the apparatus or during the upward or downwardmovement of the magnetic head 8, a contact part of the magnetic head 8is cleaned by the magnetic head cleaning portion 377 at least once. Atthis time, a circular plate of the disk cleaning portion 376 slightlyrotates so that a new surface thereof comes operable. During the nextinsertion of a disk into the apparatus, the disk is cleaned by the newsurface of the disk cleaning portion 377. Since the reproducing head gap70b of the magnetic head 8a has a width Lb, only a part of the magnetictrack 67a which corresponds to the width of the reproduced track 67b issubjected to a reproducing process.

In the thirteenth embodiment, the head gap length Lgap of the magnetichead 8a is important for the reason as follows. As previously describedwith reference to FIG. 103, the recording medium of the twelfthembodiment includes the preliminary layer 43, the print layer 49, andthe protective layer 50 which extend between the magnetic recordinglayer 3 and the magnetic heads 8a and 8b, and which have the thicknessesd2, d3, and d4 respectively. Thus, a space loss corresponding tod=d2+d3+d4 is always present. The space loss S in unit of dB is givenas:S=54.6(d/λ)  (1)where λ denotes the recording wavelength. The head gap Lgap and therecording wavelength λ has the following relation.λ=3×Lgap  (2)

According to the results of experiments, the thickness of thepreliminary layer 43 is preferably equal to 1 μm or more in view oflight blocking characteristics. Generally, it is necessary that the sumof the thicknesses of the print layer 49 and the protective layer 50 isequal to at least 1 μm. Thus, the value d generally needs to be at least2 μm, and the following relation is present.d≧2 μm  (3)By referring to the equations (1), (2), and (3), a minimum space loss Sin unit of dB is given as:S=54.6×⅔Lgap  (4)The equation (4) determines the relation between the head gap and thespace loss which is shown in FIG. 112.

Generally, to attain sufficient recording and reproducingcharacteristics, it is necessary to limit the space loss to 10 dB orless. Thus, it is found from FIG. 112 that the, head gap Lgap needs tobe set to 5 μm or more. In a conventional recording and reproducingapparatus for rotating a hard disk or a floppy disk to executeinformation recording and reproduction, a magnetic head has a sliderportion and is provided with a head gap of 0.5 μm or less. Ifinformation is recorded and reproduced into and from the recordingmedium of this invention by using such a conventional magnetic head,sufficient recording and reproducing characteristics can not be obtaineddue to the presence of the protective layer or the print layer. On theother hand, in the thirteenth embodiment, the magnetic head 8a has aslider portion 41 as shown in FIG. 111 and the head gap of the recordinghead 8a is equal to 5 μm or more so that the space loss is equal to 10dB or less as understood from FIG. 112. Thus, there is an advantage suchthat sufficient recording and reproducing characteristics can beattained during the recording and reproduction.

In the thirteenth embodiment, it is possible to execute full color labelprinting on the surface of the recording medium. It is possible to adoptthe recording medium having the same appearance as that of aconventional CD or CD ROM as shown in FIG. 101. Thus, there is an,advantage such that when a CD having the magnetic recording layer ofthis invention is used, a consumer is prevented from being confused andthe basic function of the CD standards is maintained. The magneticrecording layer uses barium ferrite which has a high magnetic coerciveforce Hc and which does not require the random orientation step. Thus,there is an advantage such that recorded data is not damaged undernormal conditions and the recording medium can be manufactured at a lowcost. The recording medium of this invention can be handled in the waysame as the way of handling a conventional CD as previously described,and thus there is an advantage such that a full compatibility betweenthe recording medium of this invention and the conventional CD can be,attained.

Next, a description will be given of countermeasures to magnetic fieldnoise transmitted from the optical head to the magnetic head.Electromagnetic noise generated by an optical head actuator 18 tends toenter the reproducing magnetic head 8b so that the error rate may beincreased. According to a first countermeasure, as shown in FIG. 114, amagnetic shield layer 69 previously described with reference to thetwelfth embodiment is provided in the recording medium 2. Thereby,electromagnetic noise generated by the actuator of the optical head 6,is prevented from entering the magnetic head 8 so that an increase inthe error rate can be prevented. In this case, when the optical headreaches an edge of the disk, electromagnetic noise tends to betransmitted from the optical head actuator to the magnetic head 8 sincethe magnetic shield is absent from an area outside the disk.

Accordingly, as shown in FIG. 110, it is preferable that the recordingand reproducing apparatus is provided with a magnetic shield 360extending around the edge of the disk to block the electromagneticnoise. According to a second countermeasure, as shown in FIG. 111, theoptical head actuator 18 is surrounded by a magnetic shield 360 made ofhigh-μ material such as permalloy or iron. The magnetic shield 360 hasan opening 362 for a lens. Thus, there is an advantage such that thetransmission of electromagnetic noise from the optical head actuator tothe magnetic head 8b is suppressed and related noise in the outputsignal from the magnetic head is remarkably decreased.

Experiments were done under the following conditions. The optical headof the recording and reproducing apparatus was held fixed, and theoptical recording portion was subjected to focusing control. On theother hand, the magnetic head was moved on the surface of the recordingmedium. During the experiments, a relative level of electromagneticnoise entering the magnetic head 8 from the optical head 6 was measured.FIG. 116 shows the relation between the measured relative level of theelectromagnetic noise and the distance between the magnetic head and theoptical head.

According to another countermeasure to noise, the noise is detected, andthe detected noise is added to a reproduced signal at an opposite phaseto reduce the noise component from the reproduced signal. As shown inFIG. 111, the magnetic recording and reproducing apparatus is providedwith a noise cancel magnetic head 8s and a noise detector such as amagnetic sensor. In a noise canceler portion 378, a reproduced signalfrom the magnetic head 8b and the detected noise are added with oppositephases respectively and at a given addition ratio A so that the noisecomponent of the reproduced signal can be canceled. By optimizing theaddition ratio A, the noise component can be adequately canceled. Theoptimal addition ratio Ao is determined by scanning a magnetic trackfree from a recorded signal and varying the addition ratio so as tominimize the level of the reproduced signal. The optimal addition ratioAo can be calibrated and updated. It is good to execute the calibrationwhen the noise level exceeds an acceptable range.

By utilizing the fact that the recording head 8a remains unused duringthe reproducing process in FIG. 110, the recording head 8a may beemployed as a noise detector. In this case, a signal outputted from therecording head 8a is inputted into the noise canceler portion 378 toremove the noise component from the reproduced signal, and the noisecancel magnetic head 8s can be omitted.

A description will now be given of the structure which includes thenoise cancel magnetic head 8s. As shown in FIGS. 129(a) 129(b), and129(c), the noise cancel magnetic head 8s is connected to the magneticheads 8a and 8b via an attachment portion 8t. When the magnetic headunit contacts the recording medium 2 as shown in FIG. 129(b), a spaceloss having a height do occurs with respect to the noise cancel magnetichead 8s.

In the case where λ=200 μm and the space loss height do is equal to 200μm or more, the level of a reproduced signal from the magnetic recordinglayer is estimated as being equal to about −60 dB and the reproductionis almost difficult. When the magnetic head is moved upward by 0.2 mm,the level of noise is reduced by only −1 dB or less as shown in FIG.116. In the case where λ=200 μm, provided that the distance between thenoise cancel magnetic head 8s and the reproducing magnetic head 8b isset to at least λ/5 equal to 40 μm, the entrance of an original signalfrom the reproducing head can be prevented. Thus, there is an advantagesuch that the transmission of electromagnetic noise from the opticalhead actuator to the reproducing magnetic head can be essentiallycompletely suppressed.

It should be noted that the noise cancel magnetic head 8s may bereplaced by a magnetic sensor such as a Hall element or an MR element.An example of the magnetic sensor is shown in FIG. 130. The drivemagnetic noise of the optical head 6 is detected by the magnetic sensor,and a signal representative thereof is added in opposite phase to themagnetic reproduced signal. Thereby, the introduced noise can be greatlyreduced. This design enables the apparatus to be further miniaturized incomparison with the magnetic head detection type.

FIGS. 172(a) and 172(b) to FIGS. 175(a) and 175(b) show examples of thedetails of the arrangement of FIGS. 129(a), 129(b), and 129(c). FIG.172(a) shows an example using a head with one gap which serves as boththe recording head 8a and the reproducing head 8b. In the case whereheads of equal sizes are, arranged as shown in FIGS. 175(a) and 175(b),a high effect is attained although the size of the composite head islarge. FIGS. 175(a) and 175(b) show an example where the width of thenoise cancel head 8s is set small to realize the miniaturization. FIGS.172(a) and 172(b) show an example using a noise cancel head 8s having auniform width. In the arrangement of FIG. 172(c), a slider 41 isprovided with a groove 41a which also forms the previously-mentionedgroove having the gap do. The slider 41 is greater than the head 8a inthe area of the surface contacting air, so that the magnetic head 8areceives a weaker air pressure. Therefore, the contact between the headand the recording medium is made better. In this case, 12>11. FIGS.173(a) and 173(b) show an arrangement in which the head gap is removedfrom the noise cancel head 8s of FIG. 171. Since, a magnetic signal isnot read out even when the noise cancel head 8s is brought into contactwith the magnetic surface of the recording medium, there is an advantagesuch that only noise can be picked up.

FIGS. 176(a) and 176(b) to FIGS. 178(a) and 178(b) show arrangementseach using a coil 499 as a noise cancel head. FIG. 176(a) shows anarrangement in which two coils 499a and 499b are located in a groove ofa magnetic head 8. It is possible to detect a noise magnetic flux 85 asin FIG. 175(b). FIG. 177(a) shows an arrangement in which coils 499a and499b are located in parallel with the gap of a head. It is possible todetect noise in the direction of the head magnetic field. FIG. 177(b)shows a noise cancel arrangement in which signals from the coils 499aand 499b are enlarged by amplifiers 500a and 500c respectively, and arecombined by an amplifier 500b into a composite signal inputted to thenoise canceler 378 of FIG. 134. FIG. 178(a) shows an arrangement inwhich vertical coils 499c and 499d are provided in addition to the coils499a and 499b parallel to the head gap. The four coils enable highernoise detection ability. By adjusting and mixing the output signals ofthe parallel coils 499a and 499b and the vertical coils 499c and 499d asshown in FIG. 178(b), it is possible to obtain a noise detection signaloptimal for noise cancel.

FIG. 179 shows a spectrum distribution having the results of measurementof actual electromagnetic noise caused by the optical pickup portion inthe apparatus equipped with the noise cancel head. As understood fromthe drawing, noise having frequencies of several KHz overlaps infrequency with the reproduction frequency band in the apparatus of thisinvention which uses a wavelength of 100 micrometers. Therefore, thisnoise significantly interferes with the reproduction. As shown in thedrawing, the noise cancel head enables the reduction of the noise in thefrequency band by about 38 dB. The noise reduction results in animprovement of the error rate during the reproduction.

According to another countermeasure to noise, the distance between theoptical head and the magnetic head is set to 10 mm or more, and thenoise is reduced by 15 dB or more as understood from FIG. 116. Thus, bysetting the distance between the optical head and the magnetic head to10 mm or more, there is provided an advantage such that the noise isremarkably reduced. In this case, it is important to maintain theaccuracy of the positional relation between the optical head and themagnetic head.

A description will now be given of a method of maintaining thepositional accuracy. As shown in FIG. 117, with respect to the opticalhead 6 and the magnetic head 8, traverse shafts 363a and 363b arerotated in equal directions in response to rotation of a common traverseactuator 23 via traverse gears 367a, 367b, and 367c. The traverse shaftsare provided with opposite screws respectively so that the optical head6 is moved in a leftward direction 51a while the magnetic head 8 ismoved in a rightward direction 51b. The respective heads meet positionalreference points 364a and 364b, and therefore positions thereof areadjusted. Thus, the optical head 6 is moved to a position above areference optical track 65a while the magnetic head 8 is moved to aposition above a reference magnetic track 67a. In this way, initialsetting of the positions of the two heads is executed. Therefore, theaccuracy of the positional relation between the two heads is maintainedduring the movements thereof. The positional setting is done at leastonce when a new recording medium 2 is inserted into the apparatus orwhen a power supply switch of the apparatus is turned on. Thereby,during later operation of the apparatus, the two heads are moved byequal distances. Thus, in the case where the optical head 8 accesses agiven optical track 65, the magnetic head 6 accurately accesses a givenmagnetic track 67 on a radius equal to the radius of thecurrently-accessed optical track 65. In the case where the optical head6 is moved thereafter, the magnetic head 8 is moved by the samedistance. Thus, as shown in FIG. 118, an magnetic track 67b and amagnetic track 65b on the same radius are accurately accessed. In thecase of access to an outermost part of the recording medium, the twoheads are positioned above tracks on a circumference having a radius L2.In the case of access to an innermost part of the recording medium, thetwo heads are moved to positions above tracks on a circumference havinga radius L1. In this case, the distance between the optical head 6 andthe magnetic head 8 is equal to 2L1. Provided that this distance is setto 10 mm or more, the level of noise transmitted from the optical headto the magnetic head is adequately small. In the case of a CD, L1=23 mmand thus the distance between the two heads is given as 2L1=46 mm, sothat the level of noise is equal to 10 dB or less as understood fromFIG. 116. Thus, there is an advantage such that an adverse influence ofthe noise hardly occurs.

As shown in FIG. 117, when a recording medium 2 is required to beinserted into the apparatus, the presence of the magnetic head 8 makesdifficult the direct insertion of the recording medium 2. Accordingly,the elevator 21 for the magnetic head lifts the magnetic head 8 and thetraverse by a significant distance, and then the recording medium isinserted into the apparatus. At this time, the previously-mentionedpositional relation between the two heads tends to be out of order. Onthe other hand, at this time, as previously described, the magnetic headcleaning portion 377 cleans the contact surface of the magnetic head 8.Then, the magnetic head 8 and the traverse are returned to givenpositions. When the magnetic head 8 and the traverse are returned to thegiven positions, the positional relation between the optical head 6 andthe magnetic head 8 is still out of order. Thus, if the magnetic head 8is moved together with the optical head 6 without correcting thepositional relation therebetween, the magnetic head 8 can not accuratelyaccess a given magnetic track 67 on a radius equal to the radius of acurrently-accessed optical track 65. The previously-mentioned positionalsetting is done at least once when the recording medium is inserted intothe apparatus. Thereby, there is provided an advantage such that asimple structure can increase the positional accuracy of access to agiven magnetic track 67 by the magnetic head 8. This is an importantfunction in realizing a home-use low-cost apparatus.

FIG. 120 shows another design in which a traverse connecting portion 366includes a flexible member such as a leaf spring. The traverseconnecting portion 366 is guided by a connecting portion guide 375. Anoptical head 6 and a magnetic head 8 are connected by the traverseconnecting portion 366 and the guide 375. Thus, the optical head 6 andthe magnetic head 8 can move together in a direction 51. Thus, it ispossible to obtain the advantage which results from the linkage betweenthe movements of the two heads as previously described with reference toFIG. 117. Since the traverse connecting portion 366 is flexible, themagnetic head 8 can be easily lifted in a direction 51a. Thus, there isan additional advantage such that the magnetic head elevator can easilylift the magnetic head 8 during the insertion of the recording medium 2into the apparatus.

The design of FIG. 117 may be modified into a design of FIG. 126 inwhich the distance between the optical head 6 and the magnetic head 8 isalways equal to a given value Lo. In this case, the optical head 6 andthe magnetic head 8 are moved in equal directions 51a and 51b. Since thedistance between the magnetic head 8 and the optical head 6 can be setlarge, there is an advantage such that the transmission of noise fromthe optical head to the magnetic head can be suppressed. This design iseffective in noise suppression especially for a small-diameter recordingmedium such as an MD.

In the previous description of this embodiment, the magnetic head andthe optical head are angularly separated by 180° with respect to thecenter of the disk as shown in FIG. 117. The angular separation betweenthe two heads may be 45°, 60°, 90°, or 120°. In these cases, providedthat the shortest distance between the two heads is 10 mm or more, it ispossible to obtain an advantage such that the level of noise can beadequately decreased.

It is preferable to adopt one of the previously-mentionedcountermeasures to noise or a combination of two or more of thepreviously-mentioned countermeasures to noise.

In the case where the electromagnetic shield with respect to the opticalhead 6 is adequately effective, the optical head 6 and the magnetic head8 can be opposed to each other in a vertical direction as shown in FIG.119. In this case, by providing positional references 364a and 364b,there is provided an advantage such that the accuracy of positionalalignment between the two heads can be increased. The above-mentionedopposed configuration has an advantage such that the apparatus can beminiaturized since all the parts can be located at one side of the disk.

Next, a recording format will be described. With respect to an opticaldisk for data, a CAV (constant angular velocity) is provided and thusthe rotational speed thereof remains the same even when the radius ofthe optical disk varies. In the application to a CD ROM, the rotation ofa disk is controlled at a CLV (constant linear velocity) so that thelinear speed remains constant although the rotational speed depends onthe radius of a track. In this case, it is difficult to adopt arecording format of a conventional floppy disk or a conventional harddisk. In the application to a CD ROM, to increase a recording capacity,this invention uses the following design. As shown at 370a, 370b, 370c,370d, and 370e in FIG. 122, the data capacities of respective tracks arelarger as they are closer to the outer edge of the disk. A head of datahas a sync portion 369 and a track number portion 371 followed by a dataportion 372 and a CRC portion 373. The capacity of the data portion 372depends on the track. The CRC portion 373 is used for error check. A gapportion 374 having no signal is set after the CRC portion 373 so that async portion 369b in a next head or others can be prevented from beingerroneously erased even when the linear velocity is different during therecording. This design has an advantage such that, in the case of a CD,the recording capacity is equal to about 1.5 times the recordingcapacity which occurs in the design where respective tracks are set toequal capacities as in a conventional floppy disk. In addition, sincethe magnetic head executes the magnetic recording and reproduction bydirectly using the CLV rotation control of the motor in response to thesignal of the optical head for the CD, there is an advantage such that amotor control circuit exclusively for the magnetic recording can beomitted.

Next, physical formats on a disk will be described. The physical formatsare of two types, a “normal mode” and a “variable track pitch mode”. Asshown in FIG. 123, magnetic tracks 67a, 67b, 67c, and 67d are located atopposite (back) sides of optical tracks 65a, 65b, 65c, and 65d, and thetracks are arranged at equal track pitches Tpo according to the “normalmode”.

This invention adopts a “variable angle” system. As shown in, FIG. 117and FIG. 119, in this invention, the angular separation between theoptical head 6 and the magnetic head 8 is equal to one of various valuessuch as 0°, 180°, 45°, and 90°. Generally, in a conventional recordingand reproducing apparatus of the rotational magnetic disk type, syncportions 369 of data, that is, indexes 455, are located at positionswith a given angle as seen from the center of the disk. In the case ofindex of the variable, angle system of this invention, as shown in FIG.123, the angle of the location of the sync portion 369 at the datastarting point can be, arbitrarily chosen with a pitch of 17.3 mm in thecircumferential direction by defining a given MSF optical block of theoptical record portion as index. In this case, as shown in FIG. 214,provided that optical frame given MSF information is recorded as indexfor every track, index information can be obtained simultaneously withtracking. In the case where “sync” following the given MSF, that is, thesync EFM modulated code data S0 and S1 in the first and second frames ofthe subcode in FIG. 213, is used as index, recording can be started withan accuracy corresponding to 170.8 μm as shown in FIG. 213. In thiscase, although magnetic recording can be accurately started from thesync portion 369 in response to the index, the magnetic recording cannot be always ended accurately. If the magnetic recording is notaccurately ended, the last portion of the record signal is written overthe sync portion 369. To prevent such a problem, it is necessary to knowthe number of optical pulses per round. Accordingly, rotation isdesigned to start from the optical record portion of index. At a midtime point, the optical beam is returned to the original track by onetrack. Thus, the reproduction is again made on the optical addresscorresponding to the index. Accurate one revolution can be performedprovided that the number of optical pulses which occurs during thisinterval is recorded. The data obtained through the measurement in thisway is recorded on the magnetic record portion of the magnetictrack-optical address correspondence table, that is, the track 0 or thetrack 1. Thereby, it is unnecessary to measure the pulse number again.

Since the physical frame number and the MSF block number correspondingto one revolution (round) are known, the magnetic recording can be endedwith a high accuracy corresponding to 170 μm. Therefore, the syncportion 369 can be prevented from being damaged while the gap 374 can beminimized so that a greater recording capacity is enabled.

In this case, it is necessary to promptly get subcode data to establishsynchronization. In FIG. 211, after an optical reproduced signal issubjected to EFM decoding, a subcode sync detector 456 obtains given MSFsubcode. In more detail, with reference to FIG. 215, an index detector457 receives the subcode from the subcode sync detector 456, andcompares it with subcode in an optical address of a given magnetictrack. When the two are equal, the index detector 457 controls a databuffer 9b to output data therefrom to start data recording from the syncof a block following the index address. Since this design uses thesubcode information which can be obtained fastest, there is an advantagesuch that a delay time is short and the reproduction is accuratelystarted with the head of a desired tune.

In the case where data in the optical address which corresponds to indexis damaged, magnetic recording on the track is difficult. To solve sucha problem, as shown in FIG. 214, an error-free optical address followingthe wrong address is defined, and the optical address MSF informationthereof is recorded on the magnetic track table of the magnetic recordportion so that the track in question can be used again.

This design makes it possible to omit a detecting circuit or a detectorfor the absolute angle of the disk. The recording of a head portion canbe started from a part of an arbitrary angle. Therefore, in the case ofa CD, data recording can be started immediately after the reading ofgiven optical address information in the optical record portion such assubcode which forms index. Thus, during reproduction, immediately afterthe optical information of the track is read out, the sync portion inthe head of magnetic data starts to be reproduced. Accordingly, a losstime being a rotation waiting time is completely removed from the periodof magnetic data recording and the period of reproduction, and asubstantive data access time is shorter. This advantage is greatespecially in the case where recording and reproducing apparatus ofequal types are used.

A description will now be given of a method accessing a magnetic track.As shown in FIG. 213, optical address information is recorded in the Qbits of the subcode in the MSF format or others. The MSF needs to beaccessed when an optical track is accessed. The width of the magnetictrack is equal to several hundreds of μm, and is greater than that ofthe optical track by two orders.

Accordingly, as shown in FIG. 221, at a step 468a, the recording andreproduction of a given magnetic track are started. At a step 468b, anoptical address is obtained by referring to the optical address-magnetictrack correspondence table. At a step 468c, a reference optical addressM0S0F0 is obtained. At a step 468d, a check is made as to whether it ismagnetic reproduction. If it is the reproduction, calculation is givenof the upper limit value M2S2F2 and the lower limit value M1S1F1 of asearch address range. A step 468f executes search for the opticaladdress. At a step 468g, a check is made as to whether the opticaladdress is in the range between the upper limit value and the lowerlimit value. At a step 468h, a work of reproducing the magnetic data isstarted. If an error is absent at a step 468i, the reproduction iscompleted. If an error is present, a check is made as to the number oftimes at a step 468j. At a step 468k, the search address range iscontracted. Then, the magnetic reproduction is executed.

If it is magnetic recording at the step 468d, a check is made at a step468m as to whether the optical index is present. If it is yes, opticaladdresses of, for example, ±5 frames, in a range narrower than that atthe step 468e are set at a step 468n. At steps 468p and 468q, theoptical head is forced to access the optical track range. At a step468r, a head is found in response to the optical index mark. At a step468s, the magnetic recording is started. At a step 468t, the magneticrecording is completed.

If the optical index mark is decided to be absent at the step 468m, astep 468u searches for the given optical address M0S0F0. In the casewhere access is done by a step 468v, when the given code data S0 and S1(see FIG. 213) in a block immediately following the block M0S0F0 aredetected at a step 468w, a head of the magnetic recording is found andset. At a step 468x, the recording is started. At a step 468t, therecording is completed.

According to the design of FIG. 221, in the case of access to themagnetic recording track, it is sufficient to search for opticaladdresses in several tens of frames. Thus, there is an advantage suchthat a time of access to the magnetic track is shorter. In the casewhere the optical address search range for recording is narrower thanthe optical address search range for reproduction, optical recording canbe more reliably executed.

Next, the “variable track pitch mode” will be described. As in a gamemachine, a general ROM disk is inserted into the apparatus. At the startof a program, information is first read out from a track of a TOCregion, and information is read out from a given track recording theprogram and information is read out from a given track recording data.This sequence is the same at every starting.

In the case where a CAV optical disk is used, it is now assumed that, asshown in FIG. 124, access is made with respect to decided tracks such asa first track 65b, a 1004-th track, 65c, a 2004-th track 65d, and a3604-th track 65e. In the case where the hybrid disk of this inventionis used, if magnetic information necessary for starting is present in amagnetic, track out of alignment with the back side of an optical trackaccessed during the starting, wasteful access to the magnetic track isexecuted in addition to access to the optical track. Thus, thecompletion of the starting is delayed commensurately. In the case of theequal intervals of the “normal mode”, there is a small possibility thatthe center of the magnetic track comes into alignment with the back sideof the optical track. Therefore, it is necessary to access anothermagnetic track, and the speed of the starting is slow also in this case.The “variable track pitch mode” of this invention features that themagnetic tracks 67b, 67c, 67d, and 67e are defined at the back sides ofthe four optical tracks 65b, 65c, 65d, and 65e which are required to beread out at the starting. The track numbers and the address informationof the optical recording portion which forms index and which correspondsto the track numbers are recorded on the TOC region of the opticalrecording portion or the TOC region of the magnetic recording portion.In the case of a CD, subcode information is recorded thereon. Data to beread out at the starting is set so as to be recorded on the magnetictrack, and the data represents a game gain item number, a progressdegree, points, a personal name, and others. Thereby, at the starting,the magnetic track which records the information necessary for thestarting is automatically accessed at the same time as access to opticaldata, and the information is read out from the magnetic track. Thus, aloss time is nullified, and there is an advantage such that the startingtime is very short., In this case, as shown in FIG. 124, the trackpitches between the tracks are equal to random values as Tp1, Tp2, Tp3,and Tp4. Therefore, although the recording capacity is slightly lowered,this design is effective to use which needs high-speed starting.

The “variable pitch mode” and the “variable angle mode” are effective tomusic use, for example, accompaniment use. In the case where thisinvention is applied to accompaniment use, personal environment settingdata can be recorded and stored which represents musical intervals forrespective music numbers desired by persons respectively, desired temposof respective music numbers, desired amounts of echo, respective desiredparameters of DSP, and others. Thereby, there is provided the followingadvantage. Provided that data setting is done once, only by inserting anaccompaniment CD into an accompaniment machine, music is reproducedautomatically with the musical intervals, the tempos, and the echoesdesired by the respective persons. Thus, it is possible for therespective persons to enjoy the accompaniments under conditions wellsuited to the abilities and the tastes of the persons. In this case,magnetic tracks at the back sides of the optical tracks 65b, 65c, 65d,and 65e for determining the heads of music numbers are defined, andpersonal accompaniment data regarding the music numbers are recorded onthe magnetic tracks 67b, 67c, 67d, and 67e. In the case where theaccompaniment on the optical track 65c is selected, the related personalaccompaniment data is recorded on the magnetic track 57 at the back sidethereof. During the start of reproduction of a given music number, themusical interval, the tempo, and the echo of the music number are set ina period of one revolution of the disk and the reproduced music startsto be outputted. Thus, also in music use, the “variable pitch mode”provides an advantage such that both optical data and magnetic data canbe quickly accessed. In general music use, this design is effective whenenvironment setting about, for example, DSP sound fields for respectivemusic numbers, is used.

In the case where this invention is applied to a CD ROM, when themagnetic coercive force Hc is set to 1,750 Oe, a RAM capacity of about32 kB can be attained. The optical recording surface of a CD ROM has aROM capacity of 540 MB. Thus, there is a capacity, difference by aboutone hundred thousand times. In most of actual products using a CD ROM,the 540-MB capacity thereof is not fully used. Generally, a CD ROM hasan unused or free capacity of at least several tens of MB. Thisinvention uses the free area of the ROM and records data compressing andexpanding programs and various data compressing reference tables intothe ROM to execute the compression of data recorded into the RAM.

The data compressing design will now be described with reference to FIG.125. In the case of a game machine, the optical recording portion 4 ispreviously loaded with information closely related to game contentspossibly required during the execution of a game program, for example,data compressing reference tables such as a place name reference table368a and a person's name reference table 368b. The free area in the ROMis large, and various reference tables can be prepared which are ofinformation having a high possible use frequency among words such asperson's names, place names, and numeral sequences. If the word“Washington” is directly recorded on the magnetic recording layer 3forming the RAM, an area of 80 bits is consumed. On the other hand, inthis invention, the data compressing reference table 368a defines“Washington” as a binary code “10”, and thus the 80-bit data iscompressed into the 2-bit data “10”. The compressed data is recorded onthe magnetic recording layer 3, and thereby the information is recordedwhile the used capacity is reduced by a factor of 1/40. It is known thatgeneral data compression techniques provide data compressioncorresponding to double or three times. Provided that use is limited,data compression by a factor of 10 or more can be done according to thisdata compressing design. Thus, the 32-kB magnetic recording capacity ofa CD ROM is substantially equivalent to the 320-kB magnetic recordingcapacity of a magnetic disk. As previously described, in the hybrid diskof this invention, the ROM area of the optical recording portion is usedin compressing data to be stored into the RAM, and thus there is anadvantage such that the logical RAM capacity is virtually increasedalthough the physical ROM capacity decreases. In FIG. 125, since thedata compressing and expanding programs are stored in the ROM of theoptical record portion, the substantive capacity of the RAM is preventedfrom decreasing. The data compressing and expanding programs may bestored in the magnetic record portion. The data compressing design mayuse a Huffman optimal coding method or a Ziv-Lempel method. In the caseof the Ziv-Lempel method, previously-prepared reference tables and Hashfunctions are recorded in the optical record portion, and thereby recorddata in the magnetic record portion can be compressed.

The overall operation of the recording and reproducing apparatus will bedescribed hereinafter with reference to FIG. 127 and FIG. 128. Thesystem controller 10 operates in accordance with a program, theflowchart of which is shown in FIG. 127 and FIG. 128.

Under conditions where the magnetic head is lifted, a step 410 places adisk into a correct position. Then, a step 411 returns the magnetic headto the normal position. A step 412 moves the optical head to a TOCtrack, and a step 413 reads out optical data from the TOC track. A firstway uses control bits, that is, Q1-Q4 bits of the subcode in FIG. 213.The magnetic layer can be recognized provided that a recording medium isdefined as being with the magnetic recording layer when Q3=1. In FIG.213, there are already used conditions of Q1, Q2, Q3, Q4=0, 0, 0, 0,conditions of Q1, Q2, Q3, Q4=1, 0, 0, 0, conditions of Q1, Q2, Q3, Q4=0,0, 0, 1, conditions of Q1, Q2, Q3, Q4=1, 0, 0, 1, and conditions of Q1,Q2, Q3, Q4=0, 1, 0, 0. Thus, conditions of Q1, Q2, Q3, Q4=0, 1, 1, 0 aredefined as a magnetic data track. In this case, the magnetic trackformat information can be recorded in the TOC. Specifically, as shown inFIG. 214, there are recorded physical positions in a CD optical recordportion which form indexes corresponding to starting points of recordingand reproduction of respective magnetic tracks. For example, in the caseof the first track, when the optical head accesses the MSF or the blockof 3-minute 15-second 55-frame, the magnetic head accesses the firsttrack. As shown in FIG. 213, the index indicating the record startingposition enables an accuracy corresponding to 17.3 mm with the MSFinformation only. The use of a given frame in a given MSF enables anindex signal to be obtained at a higher accuracy, for example, anaccuracy of 176 μm. Thus, in the case where index is made from the syncsignal in a block following the given MSF block and the recording isstarted, the reproduction can be started from a head of a desired tuneat an accuracy of 176 μm. In this case, as described with reference toFIG. 123, CLV is adopted so that indexes of the respective tracks aredifferent. The different indexes do not adversely affect actualrecording and reproduction. Since the use of the MSF information obtainsthe index in this way, it is unnecessary to provide special index. Thereadout data contains a flag representing whether or not the opticaldisk has a magnetic recording portion, address information such as CDsubcode numbers corresponding to the positions of magnetic tracks fordefaults of magnetic data, and information representing whether or notthe variable pitch mode is present. A step 414 checks the presence ofthe flag of the magnetic recording layer. When the result of the checkis Yes, an advance to a step 418 is done. When the result of the checkis No, a step 415 reads out an optical mark representing whether or notthe magnetic recording layer on the magnetic recording surface or othersis present. When a step 416 detects the absence of the optical mark, ajump to a step 417 is done so that magnetic recording and reproductionregarding the present disk are not executed.

The program enters a magnetic recording and reproducing mode at the step418, and advances to a block 402 which executes initial setting of themagnetic track. A step 419 in the block 402 moves the magnetic headdownward onto the surface of the recording medium, and a step 420 readsout magnetic data from the TOC area. Then, a step 421 lifts the magnetichead to prevent wear thereof. A step 422 checks whether or not an errorflag representing error conditions of the magnetic data is present. Whena step 423a detects the presence of the error flag, an advance to a step427a is done. The step 427a ejects the optical disk, and a step 427bindicates “clean optical disk” on a display of the apparatus. Then, astep 427c stops the program.

On the other hand, a step 424 checks whether or not the default valuerecorded on the optical recording surface is good with the opticaladdress correspondence table of the respective magnetic tracks. When theresult of the check is No, a step 426 updates the contents of a part ofthe magnetic track-optical address correspondence table in response tothe magnetic data information of the TOC track. The updated table isstored into an internal memory of the apparatus. When the result of thecheck is Yes, an advance to a step 428 is done.

When the step 428 detects the presence of a reading instructionregarding the magnetic track, an advance to a step 440 is done.Otherwise, an advance to a step 429 is done. In cases other than thevariable track pitch mode, an advance to the step 440 is done. In thecase of the variable track pitch mode, a step 430 sets an optical trackgroup number n to 0. A step 431 increments n by 1. When a step 432detects that n is equal to a final value, a jump to a step 438 is done.Otherwise, a step 433 accesses a heading optical track in the n-thoptical track group. When a step 434 detects that the default magnetictrack is good, a step 436 moves the magnetic head downward onto thesurface of the recording medium. Then, a step 437 reads out magneticdata and stores the readout data into the internal memory of theapparatus, and a return to the step 431 is done. On the other hand, whenthe optical address corresponding to the magnetic head is the defaultvalue so that bad conditions are detected, a step 435 accesses anoptical address other than the default value. Then, steps 436 and 437read out magnetic data, and a return to the step 431 is done. The step431 increments n by 1. When n reaches the final value at the step 432,reading out the optical data and the magnetic data is completed at thestep 438. Therefore, in the case of a game machine, a game program isstarted, and the game scene which occurs at the previous end isretrieved on the basis of the data recorded on the magnetic recordingportion. A step, 439 lifts the magnetic head, and an advance to a step446 is done.

When the step 429 detects the absence of the variable track pitch mode,a jump to a step 440 is, done. When the step 440 detects the absence ofthe normal track pitch mode, a jump to a step 446 is done. Otherwise, astep 441 receives an instruction of accessing the n-th magnetic track. Astep 442 derives the optical address corresponding to the n-th magnetictrack by referring to the information in the internal memory of thesystem controller 10, and a step 443 accesses the, optical address.Then, a step 444 reads out magnetic data, and a step 445 stores thereadout data into the internal memory and a jump to the step 446 isdone.

The step 446 checks whether or not a rewriting instruction is present.When the result of the check is No, a jump to a step 455 is done. Whenthe result of the check is Yes, a step 447 is executed. The step 447checks whether or not a final storing instruction is present. When theresult of the check is Yes, an advance to the step 427a (or the step455) is done. When the result of the check is No, an advance to a step448 is done. The step 448 checks whether or not data desired to berewritten is present in the internal memory of the apparatus. When theresult of the check is Yes, a jump to a step 454 is done so that themagnetic recording is not executed but only rewriting of the internalmemory is executed. When the result of the check is No, a step 449refers to the magnetic track-optical address correspondence table andaccesses the given optical track. Then, a step 450 moves the magnetichead downward, and steps 451, 452, and 453 execute reading out themagnetic data, storing the readout data into the internal memory, andlifting the magnetic head. A step 454 rewrites or updates theinformation transferred into the internal memory, and then an advance tothe step 455 is done.

The step 455 checks whether or not a final storing instruction ispresent. When the result of the check is No, an advance to a step 458 isdone. The step 458 detects whether or not the work has been completed.When the work has been completed, an advance to a step 476 is done.Otherwise, a return to the step 428 is done. When the result of thecheck at the step 455 is Yes, an advance to a step 456 is done. The step456 extracts only updated data from the magnetic data in the internalmemory, and a step 457 detects whether or not updating is present. Inthe absence of updating, an advance to a step 458 is done. In thepresence of updating, a step 459 accesses the optical address of thecorresponding magnetic track. Steps 460, 470, and 471 execute moving themagnetic head downward, recording magnetic data immediately after thedetection of the optical address, and checking the recorded data. When astep 472 detects that the error rate is large, a jump to a step 481 isdone. The step 481 lifts the magnetic head, and a step 482 cleans themagnetic head with the head cleaning portion. A step 483 executes therecording again and checks the error rate. When the error rate is good,an advance to the step 428 is done. When the error rate is bad, a jumpto the step 427a is done.

When the step 472 detects that the error rate is small, an advance to astep 473 is done. The step 473 checks whether or not the recording hasbeen completed. When the result of the check is No, a return to the step470 is done. When the result of the check is Yes, a step 474 lifts themagnetic head. A step 475 checks whether or not all the work has beencompleted. When all the work has been completed, an advance to a step476 is done. Otherwise, a return to the step 428 is done.

The step 476 lifts the magnetic head, and a step 477 cleans the magnetichead with the head cleaning portion. Then, a step 478 detects whether ornot an ejecting instruction is present. In the presence of the ejectinginstruction, a step 479 ejects the optical disk. In the absence of theejecting instruction, a step 480 stops the program.

A band pass filter tuned to a frequency band equal to a frequencydistribution of a reproduced signal from the magnetic head may beprovided in the drive circuit for the actuator 18 to remove noise.Electromagnetic noise may be reduced by the following design. Afteraccess to a magnetic head, a drive current to the actuator for theoptical head 6 is turned off. Then, reproduction is executed by themagnetic head. When the reproduction is completed, driving the actuatoris restarted.

In most of conventional CD's, a thick films of print ink are applied tothe back sides thereof by screen printing or others, so that there is aroughness of several tens of μm. When the magnetic head is brought intocontact with such a CD, print ink is removed or damaged. As shown in theON state of FIG. 115, the recording medium 2 having a magnetic shieldlayer 69 is inserted into the apparatus. In this case, the transmissionof electromagnetic noise from the actuator for the optical head 6 isremarkably suppressed as compared with the OFF state of FIG. 115 inwhich the recording medium 2 having no magnetic shield layer 69 isinserted into the apparatus. The noise is outputted from the magnetichead reproducing circuit 30, and can be easily detected. Accordingly,even when the magnetic head 8 is not brought into contact with themagnetic recording layer 3, the recording medium of this invention canbe discriminated from a conventional recording medium such as a CD. Onlywhen the recording medium of this invention which has the magneticrecording layer is inserted into the apparatus, the, magnetic head 8 isbrought into contact with the surface of the recording medium. Thus, themagnetic head is prevented from contacting the back side of a recordingmedium such as a CD or an LD which has no magnetic recording layer.Therefore, there is an advantage such that the magnetic head isprevented from damaging the optical recording surface of the recordingmedium and printed matters on the back side of the recording medium.

According to another design, in FIG. 111, a discrimination code signaldenoting the presence of a magnetic recording layer in a recordingmedium is previously recorded on a TOC area of the optical recordingportion of a CD or on an optical track portion near the TOC area. First,optical TOC information is read out from a recording medium while themagnetic head is held out of contact with the recording medium. Onlywhen the discrimination code signal for the presence of the magneticlayer is detected, the magnetic head 8 is moved into contact with therecording medium. In this design, when a conventional CD is insertedinto the apparatus, the magnetic head 8 does not contact the opticalrecording side and the label side of the recording medium. Thus, thereis an advantage such that a damage to the conventional CD can beprevented. It may be good that a given optical mark is provided on theprint surface of an optical disk, and a magnetic recording layer isdecided to be present only when the optical mark is detected.

DESCRIPTION OF THE FOURTEENTH PREFERRED EMBODIMENT

FIG. 134 shows a recording and reproducing apparatus according to aneighteenth embodiment of this invention which is similar to theembodiment of FIG. 110 except for design changes which will be describedlater. Information recording and reproduction into and from a magneticrecording portion 3 of a recording medium 2 are executed throughmodulation and demodulation responsive to an optical-system clock signal382 which is extracted from a reproduced signal related to an opticalrecording surface of the recording medium 2.

In FIG. 134, an optical reproducing circuit 38 includes a clockreproducing circuit 38a which recovers the optical-system clock signal382 from the optically reproduced signal. A clock circuit 29a containedin a magnetic recording circuit 29 subjects the optical-system clocksignal 382 to frequency division, generating a magnetic-system clocksignal 383. The magnetic-system clock signal 383 is used as a referencein modulation executed by a modulating circuit 334 in the magneticrecording circuit, 29. These conditions are shown in FIG. 216. Theoptical-system clock signal from the clock reproducing circuit 38a has afrequency of 4.3 MHz. The optical-system clock signal is down-convertedto the modulation clock signal for the MFM modulator 334 of thisinvention which has a frequency of 15-30 KHz, and magnetic recording isdone. Starting with a head of a tune is performed through the detectionof an optical address by an index detector 457 as previously described.In this case, the control of rotation of a motor is performed inresponse to the optical signal. As shown in FIGS. 218(a)-218(h), themagnetic recording is started by a periodical signal after the opticalindex.

During the reproduction of information from the magnetic recordingportion of the recording medium 2, a clock circuit 30a in a magneticreproducing circuit 30 recovers a magnetic-system clock signal 383, andthe magnetic-system clock signal 383 is used as a reference indemodulation executed by a demodulating section 30b in the magneticreproducing circuit 30.

With reference to FIG. 217, a detailed description will now be given ofoperation which occurs during the magnetic reproduction. After thereproduction is made on the optical address for the index, a powersupply to an actuator of an optical pickup portion 6 is turned off toprevent the occurrence of electromagnetic noise as shown in FIG. 218(d).Then, the magnetic reproduction is turned on, and the control of therotation of the motor and the demodulation of data are done in responseto the magnetic record signal. The reproduced signal from a magnetichead 8 is shaped by a wave shaper 466, and a clock reproducing section467 reproduces a clock signal therefrom. The reproduced clock signal isfed to a pseudo magnetic sync signal generator 462. A magnetic syncsignal detector 459 reproduces a magnetic sync clock signal, and an MFMdemodulator 30b executes demodulation into a digital signal. Thedemodulated signal is subjected by an error correcting section 36 toerror correction before being outputted as magnetic reproduced data.

The magnetic reproduced signal corresponds to frequency division of theoptical reproduced signal by a given factor. Immediately before a changefrom “optical” to “magnetic”, the signal resulting from the frequencydivision of the optical reproduced, clock signal continues to be fed toa PLL 459a of the magnetic sync signal detector 459 as referenceinformation. The central frequency of the PLL locking is set closethereto. Accordingly, upon a change from “optical” to “mangetic”, thefrequency lockup is executed in a short time according to the magneticreproduced clock PLL. In this way, the magnetic recording clock signalis generated by the frequency division of the optical reproduced clocksignal, and the magnetic recording, is done in response to the magneticrecording clock signal. This design is advantageous in that the opticalreproduced clock signal can be replaced by the magnetic reproduced clocksignal in a short time upon a change of the optical head 6 into an offstate during the reproduction of the magnetic signal. In the case wherethe optical head 6 and the magnetic head 8 fixedly travel on, the, samecircumference or different circumferences, a constant division ratio isgood. In the case where the heads travel on different circumferenceswithout being fixed, the radiuses rM and ro of the circumferences arederived and the division ratio is corrected in accordance with thederived radiuses.

A description will now be given of the way of the rotation control. Withrespect to the rotation control during the optical reproduction, apseudo optical sync signal generator 461 and a shortest/longest pulsedetector 460 in a motor rotation controller 26 of FIG. 217 generate anoptical sync signal. A motor controller 261a controls the rotationalspeed of a motor 17 at a prescribed rotational speed in response to theoptical sync signal. At this time, a change switch 465 is in a position“B”. When an optical sync signal detector 465 establishessynchronization, it feeds a changing command to the change switch 465 sothat the switch 465 changes from the position “B” to a position “A”.Thus, the motor 17 rotates at the synchronized rotational speed.

With reference to FIGS. 218(a)-218(h), at t=t2, the optical reproductionis turned off and is replaced by the magnetic reproduction. Immediatelythereafter, the MFM period T of the magnetic reproduced signal ismeasured by the wave shaper 466, and thereby the magnetic sync signalhaving a frequency of 15 KHz or 30 KHz can be obtained. The obtainedmagnetic sync signal is processed by the pseudo magnetic sync signalgenerator 462 and a frequency divider/multiplier 464 into a clock signalmatching in frequency to the optical rotation sync signal and being fedto the change switch 465. Immediately after a change from “optical” to“magnetic”, the change switch 465 moves from the position “A” to aposition “C” so that rough rotation control is executed. During a laterperiod, when the locking is established through the PLL 459a in themagnetic sync signal detector 459, the change switch 465 moves from theposition “C” to a position “D” so that accurate rotation controlresponsive to the magnetic sync signal will be started. With referenceto FIG. 218(a)-218(h), at a moment of t=t3, the magnetic reproducedsignal is synchronous with the reproduced clock signal so that themagnetic data will be continuously demodulated.

It is now assumed that an error is caused by a scratch on the recordingmedium surface at t=t4, and the error continues for a certain time tE.In this case, at t=t5, the magnetic reproduction is turned off while theoptical reproduction is turned on. During a period tR, the rotationcontrol responsive to the optical reproduced signal is done to stabilizethe rotation of the motor.

At t=t7, the period tR terminates, and the optical reproduction isturned off while the magnetic reproduction is turned on. Since the errorhas ended, the change of the rotation control from “optical” to“magnetic” is completed in a short time. At t=t8, the magnetic recordsync signal is reproduced so that data is surely reproduced. In thisway, the error is compensated. As previously described, the magneticreproduction is executed while the rotation control responsive to theoptical reproduced signal and the rotation control responsive to themagnetic reproduced signal are changed in a time division manner. Thisdesign is advantageous in that the reproduction of the magnetic signalis prevented from being adversely affected by the electromagnetic noisecaused by the optical pickup portion during the optical reproduction.Also in the case where the magnetic head 8 and the optical head 6, areseparated by 1 cm or more, the magnetic reproduction is enabled by usingthe system of FIG. 217 and FIGS. 218(a)-218(h). In this case, theoptical reproduction and the magnetic reproduction can be simultaneouslyexecuted.

As shown in FIG. 135, the velocity ω of rotation of the recording medium2 tends to fluctuate due to a variation in rotation of a drive motorwhich is generally referred to as “a wow flutter”. In a conceivabledesign where the frequency of a magnetic recording clock signal isfixed, the recording wavelength λ of a magnetically recorded signal on arecording medium 2 tends to vary even in one track according to the wowflutter. On the other hand, in the recording and reproducing apparatusof FIG. 135, since the magnetic-system clock signal 383 is generated onthe basis of the optically reproduced signal through frequency divisionand the magnetic recording is executed in response to themagnetic-system clock signal 383, the affection of the wow flutter iscanceled so that the magnetically recorded signal on the recordingmedium 2 has an accurate constant period. Therefore, there is anadvantage such that accurate recording can be realized even at a shortrecording wavelength. In addition, since a given time part of therecorded signal can be accurately located in one round of a track, a gapportion 374 (see FIG. 123) for preventing overlapped record can be setas small as possible. During the reproduction of a magnetically recordedsignal, the optical-system clock signal is subjected to frequencydivision so that the magnetic-system clock signal for demodulation canbe accurately recovered as shown in FIG. 132. Thus, a decision ordiscrimination window time 385 (Twin) for the demodulation in thereproduction can be set short, and the data discrimination performancecan be enhanced and also the error rate can be improved.

As denoted by “data 1” in FIG. 132, according to conventional two-value(bi-value) recording, only one bit can be recorded per symbol. On theother hand, in this embodiment, two bits or more can be recorded persymbol as will be described hereinafter. Specifically, as shown in“reproduce 2” in FIG. 132, a signal 384 to be magnetically recorded canbe subjected to pulse width modulation (PWM) by using an accurate timeTop determined by the optical-system clock signal 382. Four digitalvalues “00”, “01”, “10”, and “11” are assigned to four differentrecorded signals 384a, 384b, 384c, and 384d respectively which canresult from pulse width modulation of a 1-symbol waveform. Thus, twobits can be recorded per symbol so that an increased amount of recordeddata can be realized.

If recording is executed at uniform periods To, the value of λ/2 isequal to t3′−t3=To−dT and is thus smaller than the shortest recordperiod Tmin so that the accuracy of recorded information can not bemaintained regarding the signal 384d of FIG. 150. Accordingly, in thecase of the signal 384d, a new starting point is set to the moment t3and then magnetic-system clock signal is, shifted by the time dT. Thus,a discrimination (decision) window 384 for detecting “00” of “data 2” isdefined by a moment t4=t3′+dT. In addition, pulses which occur momentst5, t6, and t7 are decided to be “01”, “10”, and “11” respectively. Inthis way, the 2-bit data is demodulated.

When the pulse width modulation is designed so that eight differentmodulated signals can be generated, three bits can be recorded persymbol. When the pulse width modulation is designed so that sixteendifferent modulated signals can be generated four bits can be recordedper symbol. In these cases, a more increased amount of recorded data canbe realized.

The optical recording wavelength is 1 μm ore less while the magneticrecording wavelength equals a larger value of, for example, 10 μm to 100μm, due to a great space loss. Thus, when a pulse interval (pulse width)is measured by using the optical-system clock signal as a reference, ahigher resolution in the measurement is attained. The combination of PWMand the optical-system clock signal provides a recording capacityremarkably greater than the recording capacity realized by conventionaltwo-value recording.

In this embodiment, a region in the magnetic recording portion of therecording medium 2 is designed according to a use. In the case of a CDROM for a game machine or a CD ROM for a personal computer, a largerecording capacity is required, and thus recording regions for tracksare set over an entire surface of the recording medium 2. Music CD'sgenerally require only several hundreds of bytes for recordinginformation of music names, a music order, copy guard (protection) code,and others. Thus, in the case of music CD's, recording regions of onetrack to several tracks are set, and a remaining area except a magnetictrack portion can be used for other purposes such as a screen, printarea with unevenness.

One magnetic track may be provided on an outer area or an inner area ofthe optical recording surface side of a recording medium. In the case ofone track, as shown in FIGS. 84(a) and 84(b), recording material can beadded to an exclusive playback disk by additionally providing theelevating motor 21, the elevating circuit 22, the magnetic recording andreproducing block 9, and the magnetic head 8. This design isadvantageous in that the apparatus structure is simple and the apparatuscost is low. When one track is provided on an inner area of therecording medium, the recording capacity of that one track is relativelysmall. When one track is provided on an outermost area of the recordingmedium such as a magnetic track 67f of FIG. 124, the recording capacityof that one track is 2 KB at a wavelength of 40 μm. In this case, sincea mechanism for accessing the track is unnecessary, there is anadvantage such that the apparatus structure can be simple and small.

In this case, when a CD is inserted into the apparatus, the TOC of theoptical track 64a in FIG. 124 is read out by the optical head 6 andsimultaneously the rotational motor 17 is subjected to CLV drive inresponse to the clock signal of the TOC. Since the TOC radius of the CDis constant, rotation at a constant velocity is enabled. Under theseconditions, the magnetic recording and reproduction are executed. Thesync signal and the index signal for the magnetic recording are read outfrom the optical track 65. It is now assumed that, as shown in FIGS.84(a) and 84(b), information indicating the presence of the magneticrecording layer 3 is in an optical track 65 at or near the TOC area. Theoptical recording block 7 detects this information, driving the headelevating motor 21 and bringing the magnetic head 8 into contact withthe magnetic recording layer 3 as shown in FIG. 84(b) to execute thereproduction of the magnetic record signal.

The reproduced data is temporarily stored into the memory 34 of therecording and reproducing apparatus 1, and updating is executed inresponse to the stored data to reduce the number of times of actualmagnetic recording and reproduction and to reduce a wear.

The optical track 65a at the TOC and the outermost magnetic track 67fare simultaneously subjected to recording and reproduction, and are thusseparated by a physical distance close to 3 cm as shown in FIGS. 84(a)and 84(b). Therefore, as shown in FIG. 116, the degree of the entranceof electromagnetic noise, caused by the optical head 6 into the magnetichead 8 is reduced by 34 dB.

In the one-track system, the magnetic recording layer 3 uses an outerportion of the recording medium, and may be provided on the opticalrecording side of the recording medium. In the case where this design isapplied to a CD player having an upper lid 38a as shown in FIG. 131,since the magnetic head 8a is accommodated under the CD, the CD playercan be small in size and simple in structure.

In the case where the magnetic recording layer 3a of FIG. 131 is formedon the side of the transparent substrate 5 of the recording medium by athick film fabrication technology such as a screen printing technology,there occurs an additional thickness or height of several tens of μm toseveral hundreds of μm. This additional height causes the magnetic head8a to contact only the magnetic recording layer 3a but not contact thetransparent substrate 5. Thus, the magnetic head 8a is prevented fromdamaging the transparent substrate 5. The provision of the magneticrecording portion reduces the capacity of the optical recording portion.In the case where the magnetic head 8a is fixed with being separatedfrom the CD 2 by a distance ho of 0.22 mm or more, and where anelevating member 21b supported on the upper lid 38a forces a rubberroller 21d in a direction 51, the CD is deformed thereby so that themagnetic recording portion 3b contacts the magnetic head 8a. Thepressure applied via the rubber roller 21d enables reliable contactbetween the magnetic recording portion i3b and the magnetic head 8a, andthus enables good magnetic recording characteristics.

In this case, as shown in FIG. 98, the magnetic track 67f is provided byapplying magnetic recording material to an outermost area of the side ofthe transparent substrate 5 of the CD recording medium through a screenprinting technique. In fact, printing is done under conditions where aconventional CD is reversed to cause a back side thereof to face upwardat a screen printing step. Such a recording medium can be made by aconventional CD manufacturing line.

If the magnetic head contacts the uneven screen print area or thetransparent substrate on the optical recording side, the magnetic headand the print area or the transparent substrate tend to be damaged. Inthis embodiment, such a problem is resolved as follows. As shown in FIG.131, the magnetic recording surface of the recording medium 2 is formedwith an optical mark 387. The optical mark 387 may be provided on theopposite side of the recording medium 2. The optical mark 387 hasprinted data, such as a bar code, which represents the size of themagnetic recording region. An optical sensor 386 provided at a side ofthe magnetic head 8 serves to read out data or information representedby the optical mark 387 on the recording medium 2 in a known way.Specifically, an optical detector 386 having a combination of an LED andan optical sensor reproduces the bar code data. The optical mark 387 isgenerally located on or inward of a TOC portion of a CD. The opticalmark 387 is used in preventing a damage from being caused by themagnetic head 8.

Specifically, as shown in FIG. 131(b) and FIG. 145(a), the bar codeinformation read out from the optical mark 387 represents a region ofthe magnetic recording layer of the CD in the radial direction, thevalue of the magnetic coercive force Hc of the magnetic recordingmaterial, a secret code for a copy guard, or the identification numberof the CD. A mechanism or a circuit for moving the magnetic head 8 isactivated in response to the readout information so that the magnetichead 8 can be prevented from contacting an area of the recording medium2 except the region of the magnetic recording layer. Thus, a damage bythe magnetic head 8 can be prevented.

This embodiment may be modified as follows. In the case of a CD, an areainward of a TOC region is not provided with an optical recordingportion. As shown in FIG. 131(a), this area is formed with a transparentportion 388 extending below the optical mark 387. The optical head 6serves to read out information from the back side of the optical mark387 through the transparent portion 388. In this case, the opticalsensor 386 can be omitted.

It should be noted that the optical sensor 386 may be provided at a sideof the optical head 6. In this case, the optical sensor 386 is locatedat a fixed part of the recording and reproducing apparatus or theupper-lid type CD player of FIG. 131, and hence wiring to the opticalsensor 386 can be simplified.

In addition, the optical sensor 386 may be designed so as to detectlight which has passed through the optical mark 387. Furthermore, theoptical sensor 386 may be common to an optical sensor for detecting thepresence and the absence of a CD in the recording and reproducingapparatus.

According to one example, optical recording layers are formed atintervals through vapor deposition of aluminum or other substances sothat a circumferential bar code or a concentric-circle bar code isprovided as an optical mark. In this case, the optical mark can beformed during the fabrication of the optical recording film.

As shown in FIG. 131(b), FIG. 144(a), and FIG. 145(a), three films of amagnetic recording region 398, printed letters 45, and an optical mark387 can be formed in a step of applying screen printed material 399 to aCD twice during the formation of a magnetic recording layer 3. Theresultant print surface of the-CD has a state such as shown in FIG.145(a). When black material having a high magnetic coercive force Hc isused, a good contrast of the printed title letters 45 is attained.Provided that print ink is replaced by ink of magnetic material-having ahigh magnetic coercive force Hc in a conventional CD manufacturing line,the recording medium 2 of this invention can be made through screenprinting. Thus, the recording medium 2 of this invention, that is, a CDwith a RAM, can be made at a cost similar to the cost of manufacture ofa conventional CD.

As shown in FIG. 145(a), data “204312001” is read out from the bar code387a. A screen printing machine 399 prints data of different ID numberson CD's respectively. In the case where the screen printing machine 399is inhibited from changing the printed contents from a CD to a CD havinga copy protecting function, a circular bar code printer 400 prints a barcode 387a or numerals 387b representative of a disk ID number as shownin FIG. 144(a) and FIG. 144(b). In this case, normal ink may be used,and the resultant print surface has a state such as shown in FIG.145(b). This design is advantageous in that the user can visually readthe disk ID number. In the case where OCR numerals 387b representing adisk ID number are printed on a bar code area 387a, it is possible toconfirm the disk ID number by either visual observation or use of artoptical detector.

As shown in FIG. 144(a), a second printer 399a provides a magneticrecording region 401 of material having a high Hc of, for example, 4000Oe, which is greater than that of a magnetic recording region 398. Themagnetic recording region 401 can be subjected to reproduction by anormal recording and reproducing apparatus, but cannot be subjected torecord thereby. In a factory, a disk ID number or a secret code isrecorded thereinto. This design is advantageous in that illegal copy ofthe disk is more difficult.

As shown, in FIG. 146(a), an optical disk 2 is provided with a spaceportion 402a filled with magnetic powder 402 such as iron powder, and amagnetic portion 403 is provided at a top thereof, the magnetic portion403 has a magnetic coercive force Hc comparable with that of iron. Whenthe magnetic portion 403 is not magnetized, the magnetic powder 402 isnot attracted by the magnetic portion 403 so that letters will notappear as shown in FIG. 145(a). After the magnetic portion 403 ismagnetized by a multi-channel magnetic head, the magnetic powder 402 isattracted thereby so that the letters appear as shown in FIG. 146(b). Inthe case where OCR letters are recorded as shown in FIG. 145(c), theuser can visually read the OCR letters along direction 51a. On the otherhand, the magnetic head 8 can read outs magnetic recorded information ofa disk ID number or others from the magnetic recording portion 403.According to this design, it is sufficient that data of a disk ID numberor others is magnetically recorded in an OCR configuration disk by diskin a factory. Thus, this design is advantageous in that conventionaldisk manufacturing steps can be used.

According to another design, a magnetic recording layer 3 is provided atan outer portion of the side of a transparent substrate 5 of a recordingmedium as shown in FIG. 98, and a copy guard signal is recorded thereonin a factory. This design enables the use of a conventional caddy.Therefore, this design is advantageous in that the compatibility betweencaddies is attained.

In the case of an exclusive playback MD-type disk, only one side has ashutter. By providing a magnetic layer on a side of a transparentsubstrate of the disk, this invention can be applied thereto.

Copy protection and key unlocking will now be described. It is nowassumed that a CD contains 100 programs locked by logical keys. The userinforms the program maker (the software maker) of a disk ID number andpays a given fee. The program maker replies key numbers, correspondingto the disk ID number, to the user. For example, the key numbercorresponding to the tenth program is recorded into the TOC area of themagnetic recording region of the CD. When the tenth program isreproduced, the-key information in the magnetic recording layer and thedisk ID number in the optical mark are inputted into a use allowingprogram. If the key information is right, use of the program ispermitted according to the use allowing program. In this way, during alater period, the program can be used without any additional operation.Thus, this design is advantageous in that the program can be usedwithout inputting the key information after the key information has beeninputted once. Since a disk ID number varies from disk to disk and cannot be changed, a key can not be unlocked even if key information of apersonal disk is inputted into another personal disk. Thus, this designis advantageous in that use of a program without paying a given fee canbe inhibited.

As shown in FIG. 131, a portable CD player has a movable upper lid ordoor 389. When a CD is moved into and from the player, the upper lid 389is open. In this embodiment, the magnetic head 8 and a magnetic headtraverse shaft 363b move together with the upper lid 389. When the upperlid 389 assumes an open position, the magnetic head 8 and the upper lid389 are separate from the recording medium 2 so that the movement of therecording medium 2 into and from the player can be easily performed.When the upper lid 389 assumes a closed position, the magnetic head 8and the magnetic head traverse shaft 363b are close to the recordingmedium 2. Only when the execution of magnetic recording or reproductionis required, the magnetic head 8 is brought into contact with therecording medium 2 by a head actuator 22.

The optical head 6 is subjected to tracking operation by a traverseactuator 23, a traverse gear 367b, and a traverse shaft 363a. Thetraverse gear 367b and traverse gears 367a and 367c are in mesh witheach other. The drive force of the traverse actuator 23 is transmittedto the traverse gear 367c via the traverse gears 367a and 367b. In FIG.151, as the traverse gear 367b is rotated clockwise by the traverseactuator 23, the magnetic head traverse shaft 367b is moved in thedirection denoted by the arrow. In this way, the magnetic head 8 and theoptical head 6, are moved together by equal distances in equal radialdirections of the recording disk 2. Thus, provided that positionaladjustment of the optical head 6 and the magnetic head 8 is previouslyexecuted, the optical head 6 and the magnetic head 8 are automaticallyenabled to access an optical track and a magnetic track at oppositepositions on the surfaces of the recording medium 2 respectively whenthe upper lid 389 is closed. In this way, the mechanism for moving themagnetic head 8 and the magnetic head traverse 363b together with theupper lid 389 makes it possible to apply this embodiment to a CD player,and the recording and reproducing apparatus can be compact.

With reference to FIG. 133, a CD ROM cartridge has a lid 390 which canrotate between a closed position and an open position about a shaft 393in a direction 51c. When the lid 390 is rotated to the open position, aCD ROM or a recording medium 2 can be moved into and from the cartridge.The CD ROM cartridge has a window and a movable shutter 301 for opticalrecording.

In this embodiment, the CD ROM cartridge has a movable shutter 391 whichblocks and unblocks a window for magnetic, recording. Themagnetic-recording window is formed in the lid 390. Themagnetic-recording shutter 391 is movably supported on the lid 390. Themagnetic-recording shutter 391 and the optical-recording shutter 301engage each other via a connecting portion 392. As the optical-recordingshutter 301 is opened in the direction 51b, the magnetic-recordingshutter 391 is moved in the direction 51a so that the magnetic-recordingwindow is unblocked. In this way the magnetic-recording window and theoptical-recording window are simultaneously opened to enable themovement of a CD into and from the cartridge. The CD ROM cartridge ofthis embodiment is compatible with a conventional CD ROM cartridge.

DESCRIPTION OF THE FIFTEENTH PREFERRED EMBODIMENT

According to a fifteen embodiment of this invention, a magneticrecording layer 3 is provided on an outer surface of a cartridge 42 fora disk 2. FIG. 136 shows a recording and reproducing apparatus in thefifteenth embodiment. FIGS. 137(a), 137(b), 137(c), and FIGS. 138(a),138(b), and 138(c) show conditions of recording and reproduction whichoccur when the cartridge is inserted into, fixed, or ejected from theapparatus. FIGS. 139(a), 139(b), and 139(c) show sections of theconditions of FIGS. 137(a), 137(b), 137(c).

An optical recording and reproducing section, and a magnetic recordingand reproducing section of the apparatus of FIG. 136 are basicallysimilar to those of the apparatus of FIG. 87 and FIG. 110 except thatthe noise canceler is omitted from the magnetic recording andreproducing section.

The recording and reproducing apparatus 1 of FIG. 136 has an opening 394for inserting the disk cartridge thereinto. FIG. 136 shows conditionswhere the cartridge 42 has been inserted in a direction 51.

In the case where the cartridge 42 is inserted into the recording andreproducing apparatus 1 as shown in FIG. 137(a), an optical sensor 386reads out an optical mark 387 such as a bar code provided on a part of alabel portion 396 of the cartridge. An optical reproducing circuit 38 inFIG. 136 reproduces data, and a clock reproducing circuit 389 reproducesa sync clock signal. The reproducing data is fed to a system controller10. If a magnetic recording layer 3 is decided to be present, a headmoving command is fed to a head actuator 21 so that a head elevatingsection 20 moves magnetic heads 8a and 8b toward the magnetic recordinglayer 3. Data in the magnetic recording layer 3 is read out by themagnetic heads 8a and 8b, being demodulated into original data bydemodulators 341a and 341b of magnetic reproducing circuits 30a and 30b.At this time, a clock reproducing circuit 38a reproduces a sync clocksignal on the basis of a signal in the optical mark 387. The use of thesync clock signal enables reliable demodulation even if a runningvelocity fluctuates. Therefore, this design is advantageous in that thedata in the magnetic recording layer 3 can be surely read out even ifthe running velocity fluctuates due to a shock upon the insertion of thecartridge 42 into the apparatus. In the case where identificationinformation of a cartridge ID number, a software title, or others isrecorded in, the optical mark 387, data management can be done cartridgeby cartridge.

Generally, only a single magnetic head 8 suffices. As shown in FIG. 136,two magnetic heads may be provided to execute the recording andreproduction of same data twice. This design improves a reliability inthe readout of the data. A combining circuit 397 combines error-freeportions of data 1 and data 2 into error-free complete data, therebyreproducing data containing index information such as TOC datainformation which is stored into an IC memory 34. The TOC data containsinformation of the results and the processes of the recording andreproduction, and the previous directory of the cartridge 42. Therefore,the progress of use and the contents of the optical disk can be detectedupon the insertion of the cartridge 42 into the apparatus.

While the cartridge 42 remains in the apparatus as shown in FIG. 137(b),magnetic recording and reproduction are arbitrarily done to add newinformation or to delete the recorded information. In this case, thecontents of the TOC needs to be changed. In this invention, the TOC datain the IC memory 34 is updated without rewriting the data in themagnetic recording layer 3. Thus, the new TOC data in the IC memory 34is different in contents from the old TOC data in the magnetic recordinglayer 3. When the cartridge 42 is ejected from the apparatus as shown inFIG. 137(c), the data in the magnetic recording layer 3 is updated. Thenew data is immediately reproduced by the magnetic head 8b, beingchecked and confirmed.

In the presence of multiple tracks such as three tracks, data updatingis executed only on one, for example, a second one, of the tracks whichrequires a TOC data change, and thereby the number of errors is reducedduring the recording. In this case, when the cartridge 42 is ejectedfrom the apparatus as shown in FIG. 137(c), only third one of the tracksis subjected to recording by the magnetic head 8b.

In the presence of two heads as shown in FIGS. 137(a), 137(b), and137(c), a recorded signal 68 is simultaneously read out by the magnetichead 8a, and error check is executed thereon. As shown in FIG. 139(c), amagnetic signal 68a which has been recorded by the magnetic head 8b canbe checked by using the magnetic head 8a. If an error is present, anerror message is indicated on a display section 16 of the recording andreproducing apparatus 1. An indication may also be given whichrepresents “please insert the cartridge into the body again”. Inaddition, a warning sound may be generated by a buzzer 397. Therefore,the user is forced to insert the cartridge 42 into the insertion portion394 of the apparatus again. In the case where the cartridge 42 has beeninserted into the apparatus again, TOC data is recorded once again whenthe cartridge 42 is ejected from the apparatus. The second recording hasno error at a high probability. If such a process is repeated a givennumber of times, the magnetic recording layer 3 of the cartridge 42 isdecided to be damaged while the ID number of the optical mark 387 isrecorded. During a later period, when the cartridge 42 having thisrecorded ID number, a command of lowering the magnetic head 8 is notissued to unexecute the readout of the data. The data of the ID numberis stored in the IC memory 34 with being backed up. In this way, TOCdata can be reliably recorded and reproduced into and from eachcartridge 42. This design is advantageous in that the addition of asimple arrangement enables the detection of a table of contents of arecording disk upon the insertion of a related cartridge into theapparatus. For a recording medium side, the attachment of a magneticlabel to a conventional cartridge 42 suffices.

DESCRIPTION OF THE SIXTEENTH PREFERRED EMBODIMENT

A sixteenth embodiment of this invention is similar to the fifteenthembodiment except that a disk cartridge is replaced by a tape cartridge.Specifically, a magnetic layer 3 provided with a protective layer 50which has been described with reference to FIG. 103 is attached to anupper portion of a tape cartridge 42 for a recording and reproducingapparatus 1.

FIG. 140 shows a whole arrangement which is similar to the arrangementof FIG. 136 except for design changes indicated hereinafter. Therecording and reproducing apparatus 1 of FIG. 140 has an insertionopening 394 for a VTR cassette or cartridge 42 FIG. 140 shows conditionswhere the cassette 42 is being inserted into the apparatus along adirection 51. FIGS. 141(a), 141(b), 141(c), 142(a), 142(b), and 142(c)show conditions where the cassette is placed in and out of theapparatus. FIGS. 142(a), 142(b), and 143(c) show a transverse section ofa magnetic head portion with the cassette being placed in the apparatus.

In the case where the cartridge 42 is inserted into the recording andreproducing apparatus (VTR) 1 as shown in FIG. 142(a), an optical sensor386 reads out an optical mark 387 provided on a part of a label portion396 of the cartridge. Bar code information and a sync signal arerecorded on the optical mark 387. An optical reproducing circuit 38 inFIG. 140 reproduces data, and a clock reproducing circuit 389 reproducesa sync clock signal. The reproduced data is fed to a system controller10. If a magnetic recording layer 3 is decided to be present, a headmoving command is fed to a head actuator 21 so that a head elevatingsection 20 brings magnetic heads 8a and 8b into contact with themagnetic recording layer 3. Data in the magnetic recording layer 3 isread out by the magnetic heads 8a and 8b, being demodulated intooriginal data by demodulators 341a and 341b of magnetic reproducingcircuits 30a and 30b. At this time, a clock reproducing circuit 38areproduces a sync clock signal on the basis of a signal in the opticalmark 387. The use of the sync clock signal enables reliable demodulationeven if a running velocity fluctuates. Therefore, this design isadvantageous in that the data in the magnetic recording layer 3 can besurely read out even if the running velocity fluctuates due to a shockupon the insertion of the cartridge 42 into the apparatus. In the casewhere index information such as a cartridge ID number or a softwaretitle is recorded in the optical mark 387, data management can be donecartridge by cartridge (cassette by cassette).

Generally, only a single magnetic head 8 suffices. Two magnetic headsmay be provided to execute the recording and reproduction of same datatwice. This design improves a reliability inn the readout of the data. Acombining circuit 397 combines error-free portions of data 1 and data 2into error-free complete data, thereby reproducing data containing TOCdata and others which is stored into an IC memory 34. The TOC datacontains the absolute address which occurs at the moment of the end ofthe preceding operation of the cartridge 42, and the absolute addressesof the start and the end of respective segments and respective tunes.Accordingly, when the magnetic data is reproduced, the current tapeabsolute address is known which occurs at the moment of the insertion ofthe cartridge 42 into the apparatus. The contents of an absolute addresscounter 398 in the system controller 10 are updated in response to theinformation of the absolute address.

It is now assumed that the tape stores tunes. For example, it is knownthat the current address corresponds to 1-minute 32-second of an eighthtune while the current absolute address corresponds to 62-minute12-second. In the case where a point at an absolute address of 42-minuteand 26-second in a sixth tune is desired to be accessed, the tape isrewound by an amount corresponding to an absolute address of 19-minute46-second while referring to the data from an absolute address detectinghead 399 so that the current tape position can be quickly accorded withthe head of the sixth tune. The interval between the current tapeposition and the desired tape position is previously known, so that theaccess speed can be high by accelerating, moving, and decelerating thetape at optimal rates. In addition, the list of the TOC information canbe immediately indicated upon the insertion of the tape cassette intothe apparatus.

While the cartridge 42 remains in the apparatus as shown in FIG. 141(b),magnetic recording and reproduction are arbitrarily done to add a newtune or to delete a recorded tune. In this case, the contents of the TOCneeds to be changed. In this invention, the TOC data in the IC memory 34is updated without rewriting the data in the magnetic recording layer 3.Thus, the new TOC data in the IC memory 34 is different in contents fromthe old TOC data in the magnetic recording layer 3.

In the presence of multiple tracks such as three tracks, data updatingis executed only on one, for example, a second one, of the tracks whichrequires a TOC data change, and thereby the number of errors is reducedduring the recording. In this case, when the cartridge 42 is ejectedfrom the apparatus as shown in FIG. 137(c), only third one of the tracksis subjected to recording by the magnetic head 8b.

In the presence of two heads as shown in FIGS. 137(a), 137(b), and137(c), a recorded signal 68 is simultaneously read out by the magnetichead 8a, and error check is executed thereon. As shown in FIG. 139(c), amagnetic signal 68a which has been recorded by the magnetic head 8b canbe checked by using the magnetic head 8a. If an error is present, anerror message is indicated on a display section 16 of the recording andreproducing apparatus 1. An indication may also, be given whichrepresents “please insert the cartridge into the body again”. Inaddition, a warning sound may be generated by a buzzer 397. Therefore,the user is forced to insert the cartridge 42 into the insertion portion394 of the apparatus again. In the case where the cartridge 42 has beeninserted into the apparatus again, TOC data is recorded once again whenthe cartridge 42 is ejected from the apparatus. The second recording hasno error at a high probability. If such a process is repeated a givennumber of times, the magnetic recording layer 3 of the cartridge 42 isdecided to be damaged while the ID number of the optical mark 387 isrecorded. During a later period, when the cartridge 42 having thisrecorded ID number, a command of lowering the magnetic head 8 is notissued to unexecute the readout of the data. The data of the ID numberis stored in the IC memory 34 with being backed up. In this way, TOCdata can be reliably recorded and reproduced into and from each VTR tapecartridge 42. This design is advantageous in that the addition of asimple arrangement enables the TOC function which does not need anyadditional access time. For a recording medium side, the attachment of amagnetic label to a conventional cartridge 42 suffices.

DESCRIPTION OF THE SEVENTEENTH PREFERRED NEMBODIMENT

A seventeenth embodiment of this invention relates to a method ofunlocking a key of a given program in an optical disk such as a CD ROM.As shown in FIG. 147, an ID number which varies from disk to disk isrecorded on an optical mark portion 387 of a CD. The data representing,for example, “204312001” is read out from the optical mark portion 387by an optical sensor 386 having a combination of a light emittingsection 386a and a light receiving section 386b. The readout data is putinto a disk ID number area (OPT) of a key management table 404 in a CPU.

To enhance the copy guard function, there is provided a high Hc portion401 of barium ferrite having a magnetic coercive force Hc of 4000 Oe. Ina factory, ID number data (Mag) of, for example, “205162”, ismagnetically recorded on the high Hc portion 401. The ID number data isread out from the high Hc portion 401 by a normal magnetic head. Thereadout data is put into a disk ID number area (Mag) of the keymanagement table 404.

With reference to FIG. 241(a), in the case where a magnetizing machine540 of FIG. 242(a)-242(d) is used, a step of recording an ID number intoa medium 2 can be executed in one second or shorter. As shown in FIGS.242(a) and 242(b), the magnetizing machine 540 is of a ring shape. Asshown in FIGS. 242(c) and 242(d), the magnetizing machine 540 has aplurality of magnetizing poles 542a-542f and windings 545a-545f. Acurrent from a magnetizing current generator 543 is fed via a currentdirection changing device 544 to the windings 545a-545f so that anarbitrary magnetization direction can be attained.

FIG. 242(d) shows a case where magnetization directions of S, N, S, S,N, and S poles are set from the left. In this case, magnetic recordsignals of directions denoted by the arrows 51a, 51b, 51c, and 51d areinstantaneously recorded into a magnetic recording layer 3. Recordingcan done into a magnetic material having a high Hc of 4000 Oe. Thus, asshown in FIG. 242(a), a CD into which an ID number is recorded can bemade in the same time interval as that in the prior art of FIG. 241 (b).

As previously described, in the case where a magnetizing machine 540 ofFIG. 242(a)-242(d) is used, a step of, recording an ID number into amedium 2 can be executed in one second or shorter. Thus, the magnetizingmachine 540 is more suited, to a step with a greater throughput. Aspreviously described, as shown in FIGS. 242(a) and 242(b), themagnetizing machine 540 is of a ring shape.

As shown in FIGS. 242(c) and 242(d), the magnetizing machine 540 has aplurality of magnetizing poles 542a-542f and windings 545a-545f. Acurrent from a magnetizing current generator 543 is fed via a currentdirection changing device 544 to the windings 545a-545f so that anarbitrary magnetization direction can be attained. FIG. 242(d) shows acase where magnetization directions of S, N, S, S, N, and S poles areset from the left. In this case, magnetic record signals of directionsdenoted by the arrows 51a, 51b, 51c, and 51d are recorded on a giventrack in a magnetic recording layer 3 in a short time, for example,several ms. In the case of the magnetizing machine 540, since a greatcurrent can be fed, recording can done into a magnetic material having ahigh Hc of 4000 Oe. Thus, as shown in FIG. 241(a), and ID number can berecorded in a work time comparable to that in the prior art of FIG.241(b), and a CD can be made without changing a flow of steps. In thecase where the magnetizing machine 540 is used, an ID number can bemagnetically recorded without rotating a medium 2. Accordingly, it ispossible to increase the throughput. The absence of rotation of a mediumprovides an advantage such that matters can be accurately printed on themedium with a given angle after an ID number is recorded as shown inFIG. 241(a).

As previously described, in the case of the magnetizing machine 540,since a great current can be fed, recording can done into a magneticmaterial having a high Hc of 4000 Oe. It is preferable that a mediumuses such a high-Hc magnetic material in a region corresponding to agiven track, and an ID number is recorded on the given track by themagnetizing machine 540. In this case, the recorded ID number can not berewritten by a normal magnetic head 8, and an improvement can beattained on the security of a password related to the ID number. Itshould be noted that the normal magnetic head 8 is designed to becapable of operating on a magnetic recording layer with an Hc of 2700 Oeor less.

In this invention, as shown in FIG. 243, data of a physical arrangement(layout) table 532 of a disk and a signal from a generator 546 for aunique ID number are mixed by a mixer 547 in a manner such that it isdifficult to separate them in the absence of a separation key. Themix-resultant signal and a separation key 548 are fed to a secret codedevice 537, being made into a secret code 538. The secret code 538 isrecorded on a magnetic recording track 67 after a shaping step. Thesecret code 538 may be recorded on an optical recording track 65 in anoriginal disk making step.

In a recording and reproducing apparatus 1, a secret code decoder 543decodes a secret code, and a separator 549 divides the output signal ofthe decoder 543 into an ID number 550 and a disk physical arrangement(layout) table 532 in response to the separation key. As will bedescribed later with reference to FIG. 238 and FIG. 240, a check is madeas to whether or not the current disk is an illegal disk. When thecurrent disk is judged to be an illegal disk, operation of the currentdisk is stopped.

In the system of FIG. 243, a word of the secret code 538 recorded on amagnetic recording track 67 varies from a disk to disk. Each disk usesthe previously-indicated illegal-copy guard of this invention so that itis difficult to copy information in an optical recording portion of aCD. According to the system of FIG. 243, a plurality of differentoriginal disks are present for one disk, and a word of the secret code538 varies from a disk to disk. Thus, it is difficult to confirm thattwo disks are the same original disk only by referring to the secretcode. It is necessary to read out all information in a disk physicalarrangement (layout) table 532 of each disk, and to check whether or notthe two disks are the same original disk by referring to the readoutinformation. Checking all data of an address, an angle, tracking, a pitdepth, and an error rate requires a large-scale apparatus, and needs acertain length of time for confirmation. Thus, it is difficult to searchfor an original disk same as a disk or a CD related to a known password.This is advantageous in the illegal-copy guard since it is difficult toillegally rewrite an ID number of a disk.

A specific operation sequence will be described with reference to FIG.148. In the case where a command of starting a program having a number Ncomes at a step 405, a reading process is done to check whether keyinformation of the program is recorded on a magnetic track at a step405a. At this time, a recording current is driven in the magnetic headto erase data from the magnetic track. In the case of a formal disk, keyinformation is not erased because of a high Hc. In the case of anillegal disk, key information is erased. Next, at a step 405b, a checkis made as to whether key data or a password is present. If it is no,the user is informed of a key inputting command as shown in FIG. 170 ata step 405c. Then, at a step 405d, the user inputs, for example,“123456”. At a step 405e, a check is made as to the input data iscorrect. If it is no, the operation stops, at a step 405f and anindication of “a copy disk and a wrong key” is given on a displayscreen. If it is yes, an advance to a step 405g so that the key data foropening the program having the number N is recorded on the magnetictrack of the recording medium 2. Then, a jump to a step 405i is done.

Returning to the step 405b, if it is yes, an advance to a step 405h isdone. At the step 405h, the key data of the program having the number Nis read out. At a step 405i, a disk ID number (OPT) is read out from theoptical recording layer. At a step 405j, a disk ID number (Mag) is readout from the magnetic recording layer. At a step 405k, a check is madeas to the ID numbers are correct. If it is no, an indication of “a copydisk” is given on the display screen at a step 405m and the operationstops. If it is yes, secret code unlocking calculation is executed amongthe key data, the disk ID number (OPT), and the disk ID number (Mag) tocheck whether the data is correct. A step 405p executes a check. If itis no, an error indication is executed at a step 405q. If it is yes, astep 405s starts the program having the number N to be used.

According to this invention, for example, 120 tunes are recorded into aCD while being compressed by a factor of ⅕. For example, 12 tunes amongthe 120 tunes have no keys and thus can be reproduced freely while theother tunes are locked by keys. Such a CD is sold at a pricecorresponding to a copyright fee of the 12 tunes. The user is informedof data of the keys by paying an additional fee. Then, the user canenjoy the other tunes as shown in FIG. 147.

According to this invention for example, a plurality of, game programsare recorded into a CD. For example, only one game program thereamonghas no key and thus can be reproduced freely while the other gameprograms are locked by keys. Such a CD is sold at a price correspondingto a copyright fee of one game program. The user is informed of data ofthe keys by paying an additional fee. Then, the user can enjoy the othergame programs as shown in FIG. 147.

The use of an audio expansion block 407 enables a CD to contain a370-minute length of music. A desired tune can be selected by unlockingthe related key. When a key is unlocked once, key data is recorded.Accordingly, during a later period, it is unnecessary to input the keydata. This invention can also be applied to a CD forming an electronicdictionary, a CD containing video information, or a CD containinggeneral application programs. It should be noted that the ID number inthe high Hc portion 401 may be omitted to lower the cost.

With reference to FIG. 234, a description will now be given of amastering apparatus 529 for making an original disk for a CLV typeoptical disk such as a CD. In the case of a CD, while a linear velocitycontroller 26a maintains a linear velocity in the range of 1.2 m/s to1.4 m/s, an optical head 6 subjects a photosensitive member on a disk 2to a light exposure process in which pits representing a latent imageare recorded thereon by a light beam. In the case of a CD, a trackingcircuit 24 increases a radius “r” by a pitch of about 1.6 μm perrevolution so that pits are recorded in a spiral configuration. Thus, asshown in FIG. 236(a), data is spirally recorded.

As previously described, in the case of a CLV optical disk such as aCD-ROM, recording in a spiral configuration is done with a constantlinear velocity previously set in the range of 1.2 m/s to 1.4 m/s. Inthe case of CLV, the amount of recorded data in one round varies as thelinear velocity changes. When the linear velocity is low, a dataarrangement (layout) 530a such as shown in FIG. 236(a) is provided. Whenthe linear velocity is high, a data arrangement (layout) 530b such asshown in FIG. 236(b) is provided. In the case where a normal masteringapparatus is used, a legal (ligitimate) CD and an illegal CD havedifferent data arrangements (layouts) 530. A normal mastering apparatusfor a CD can set a linear velocity at an accuracy of 0.001 m/s. Aspreviously described, an original disk is formed at a constant linearvelocity. Even in the case where an original disk for a 74-minute CD isformed at a linear velocity of 1.2 m/s with such a high accuracy, theoutermost track has an error corresponding to 11.78 rounds in a plusside. In other words, an available data arrangement (layout) 530b is ina condition where an outermost portion has an angular errorcorresponding to the product of 11.783 rounds: and 360 degrees. Thus, asshown in FIG. 236(a) and FIG. 236(b), a legal (legitimate) CD and anillegal CD are different from each other in data arrangements (layouts)530, that is, addresses 323a-323x of A1-A26. For example, in the casewhere arrangement zones 531 being Z1-Z4 are defined according todivision into four, the arrangement zones 531 of the addresses 323 ofA1-A26 are different. Thus, in the case where physical position tables532, that is, tables of correspondence between addresses 323 andarrangement zones 531 of two CD's, are formed, physical position tables532a and 532 are different as shown in FIG. 236(a) and FIG. 236(b). Thiscondition can be used in discriminating a legal (ligitimate) CD and anillegal CD.

As shown in FIG. 238, in this invention, a physical position table 532is made during or after the manufacture of an original disk for CD's,and a secret coding device 537 executes coding into a secret code byusing a one-directional function in an open secret code key system of anRSA type. The resultant secret code is recorded into an optical ROMportion 65 of a CD 2 or a magnetic recording track 67 of a CD 2a.

In a drive side, a secret code 538b is reproduced from a CD 2 or 2a, anda physical arrangement (layout) table 532 is recovered by using a secretcode decoding program 534 reproduced from the CD. By using a disk checkprogram 533a reproduced from the CD, disk rotation information 335 withrespect to an actual CD address 38a is obtained from an index or arotation pulse signal from a previously-mentioned FG. The information iscollated with data in the physical arrangement (layout) table 532. Ifthe result of the collation is OK, starting is done. If the result ofthe collation is NO, the current disk is judged to be an illegal CD sothat the operation of the software program and the reproduction of amusic software are stopped. Since the illegal CD shown in FIG. 236(b)differs from a legal (legitimate) CD in the physical position table532b, the illegal CD is rejected. An illegal disk with a copied secretcode is rejected. If the secret code encoding program 537 can not bedecoded, an illegal CD will not start to operate. Thus, there is a greatadvantage such that the reproduction of an illegal CD is prevented.

In this invention, since the secret code decoding program 534 and thedisk check program 533a are provided in a medium side rather than adrive side, they can be changed press by press or title by title ofCD-ROM's. This is advantageous in a guard against illegal copy.

This invention uses a one-directional function of an open secret codekey system of the RSA type such as shown in FIG. 238. For example, it ispossible to use a calculation equation as C=E(M)=M^(e) _(mod)n. One ofthe key, that is, the secret code decoding program on a CD-ROM, is opento the public while the other of the key, that is, the secret codeencoding program, remains secret. In the system of FIG. 238, the secretcode decoding program, 534 is provided in a medium side rather than adrive side. If the secret code encoding program 537 is leaked, it isgood to change both the secret code decoding program and the secret codeencoding program to recover the guard against illegal copy.

In the mastering apparatus 529 of this invention, as shown in FIG. 234,a CLV modulation signal generator 10a generates a CLV modulation signal,which is fed to a linear velocity modulator 26a or a time base modulator37a of an optical record circuit 37 to execute CLV modulation. As shownin FIG. 235(a), the linear velocity modulator 26a modulates the linearvelocity at random in the range of 1.2 m/s to 1.4 m/s. A similar processcan be implemented by modulating a signal by the time base modulator 37awhile holding the linear velocity constant. It is difficult toaccurately detect the linear velocity modulation from an original CD.The random modulation makes it difficult for the mastering apparatus,which makes the original disk, to copy the disk. As a result of therandom modulation, original disks differ from each other. Therefore, itis difficult to completely copy a CD with the linear velocitymodulation. Since the linear velocity varies only in the allowablestandard range of 1.2 m/s to 1.4 m/s, data is accurately from a CD by anormal CD-ROM player.

A start point S is defined in the case where equal data is recorded on agiven optical track 65a at a constant linear velocity of 1.2 m/s asshown in FIG. 235(b). It is now assumed that an end point A1 at whichthe data has been recorded agrees with a position of 360 degrees. Underthese conditions, in the case where the linear velocity is increasedfrom 1.2 m/s to 1.4 m/s at a constant rate in one revolution, thephysical position 539a of an address A3 agrees with a physical position539b offset by 30 degrees. In the case where the linear velocity isincreased in a ½ revolution the physical position 539a agrees with aphysical position 539c offset by 45 degrees. Thus a position can bechanged by 45 degrees or less in one round. Since a normal masteringapparatus for CLV generates only one rotation pulse per revolution, theerror is accumulated into a positional shift of 90 degrees until tworevolutions are completed. The linear velocity modulation of thisinvention causes a positional deviation of 90 degrees between a legal(legitimate) original disk and an illegal original disk. A CD formed byillegal copy can be detected by sensing this positional deviation. It isgood that the resolution of sensing of the positional deviation ischosen to correspond to 90 degrees or less. Thus, in the case where thelinear velocity is varies in the range of 1.2 m/s to 1.4 m/s, an illegalCD can be detected by setting at least four 90-degree divided zones Z1,Z2, Z3, and Z4 as shown in FIGS. 236(a) and 236(b).

The mastering apparatus of FIG. 234 has a rotational angle sensor 17a.In the mastering apparatus, a physical position table 532 is generatedfrom address information 32a of input data and positional information32b of a rotational angle from a motor 17, being made into a secret codeby a secret code encoder 537 and being recorded on an outer portion ofan original disk 2 by an optical record circuit 37. Thereby, the secretcode of the physical arrangement (layout) table 532 can be recorded onan optical track 65 of a disk 2 in FIG. 238 during the manufacture ofthe original disk. The resultant disk can be subjected to a reproducingprocess by a normal CD-ROM drive without any-magnetic head. In thiscase, as shown in FIG. 238 and FIG. 239, the drive is required to have adisk rotational angle sensor 335. It is sufficient that this sensingmeans can detect a 90-degree zone at a relative position related to anaddress 323. Thus, it is unnecessary to use a complicated sensor such asan angle, sensor in the sensing means.

A way of detecting a relative position will now be described. As shownin FIG. 237(a), one rotation pulse of a motor or one index signal of anoptical sensor is generated per revolution of a disk. This period issubjected to time division as shown in FIG. 237(b). In the case ofdivision into six zones, signal position time slots Z1-Z6 aredetermined. As previously described, address signals 323a and 323b aregenerated from the sub code of a reproduced signal. From signal positionsignals, it is possible to detect that the address A1 is in the zone Z1while the address A2 is in the zone Z3.

With reference to FIG. 239, in a recording and reproducing apparatus 1,a signal is reproduced by an optical reproduction circuit 38. If aphysical arrangement (layout) table 532 is present in an optical track,advance from a step 471b to steps 471d and 471e is done in FIG. 240. Ifit is no at the step 471b, a check is made at a step 471c as to whetheror not secret code data is present in a magnetic record portion 67. Ifit is no, advance to a step 471r is done to allow start. If it is yes,advance to the steps 471d and 471e is done so that the secret code datais reproduced. In addition, a secret code decoding program for a secretcode decoder 534 which is stored in a ROM of the drive or the disk isstarted, and the secret code is decoded. At a step 471f, the physicalarrangement (layout) table 532, that is, a zone address correspondencetable of An:Zn, is made. At a step 471w, a check is made as to whetheror not a disk check program is, present in the medium. If it is no,advance to a step 471p is done. If it is yes, the disk check programrecorded in the disk is started at a step 471g. In the disk checkprogram of the step 471f. “n=0” is executed at a step 471h, and “n=n+1”is executed at a step 471i. At a step 471j, the drive side is operatedto search for an address An of the disk 2, and to reproduce the address.At a step 471k, the previously-mentioned address position sensing means335 detects positional information Z′n and outputs the information. At astep 471m, a check is made as to whether or not “n=Zn” is satisfied. Ifit is no, the current disk is judged to be an illegal CD at a step 471uand a display 16 is controlled to indicate “illegal copy CD”. Then,stopping is executed at a step 471s. If it is yes at the step 471m, acheck is made at a step 471n as to whether or not “n=last” is satisfied.If it is no, return to the step 471i is done. If it is yes, advance to astep 471p is done. At the step 471p, a check is made as to whether ornot the disk check program is present in the RAM or the ROM in the driveside. If it is no, a software is started at the step 471r. If it is yes,the disk check program is started at a step 471q. Its contents are thesame as those of a step 471t. If it is no, advance to steps 471u and471s is done. If it is yes, a software in the disk starts to bereproduced at the step 471r.

As previously described, a linear velocity is varied in the range of 1.2m/s to 1.4 m/s during the formation of a disk. When a conventional CDplayer subjects such a disk to a reproducing process, an original signalcan be recovered without any problem. A mastering apparatus is able toexecute a cutting process at an accuracy whose minimum value correspondsto a linear velocity of 0.001 m/s. With respect to CD's, there areprovided such standards for a mastering apparatus that a linear velocityis equal to ±0.01 m/s. A linear velocity can be increased from 1.20 m/sto 1.22 m/s as shown in FIGS. 244(a) and 244(b) while the standards aremet. In this case, as shown in FIGS. 244(c) and 244(d), a physicalarrangement of an angle of a same address shifts from a state 539a to astate 539b by an angle of 5.9 degrees per revolution of the disk. Asshown in FIG. 246, a recording and reproducing apparatus is providedwith a rotational angle sensor 335 for detecting an angular shift of 5.9degrees, and thereby a difference between physical arrangements can bedetected. In the case of a CD, it is good to provide a rotational anglesensor 335 having a resolution of 6 degrees, that is, having an angulardivision into 60 or more per revolution.

The rotational angle sensor 335 has a structure such as shown in FIG.249. Pulses outputted from a rotational angle sensor 17a such as an FGassociated with a motor 17 are subjected to time division by a timedivision circuit 553a in an angular position detector 553 of a diskphysical arrangement detector 556. Even in the case where one rotationpulse signal occurs per revolution, when a time accuracy of ±5% isavailable, division into 20 can be done so that an angular resolution ofabout 18 degrees can be attained. It should be noted that the operationof the rotational angle sensor 335 has been described with reference toFIGS. 237(a), 237(b), and 237(c).

In the case of a CD, since there is an eccentricity of ±200 μm, an errorin measurement of an angle is caused by the eccentricity. In the case ofa disk according to the CD standards, an error in the angularmeasurement which corresponds to 0.8 degree or less in P—P is caused byan eccentricity. As shown in FIG. 249, the angular position detector 553is provided with an eccentricity detector 553c for detecting aneccentricity, and an eccentricity corrector 553b executes correctivecalculation to compensate for the eccentricity.

The detection of the eccentricity and the calculation of the correctivevalue will now be described. In the absence of an eccentricity as shownin FIG. 252(a), the center of a triangle defined by three points A, B,and C on a common radius is coincident with the center 557 of the diskwhen “θa=θb=θc” is satisfied. In fact, as shown in FIGS. 252(b), thereoccurs an offset (an eccentricity) 559 due to an, eccentricity of thedisk or an error in the position of the disk relative to the apparatus.As shown in FIG. 252(b), the relative angles of the addresses of thethree points A, B, and C are detected by the angle sensor 335, and thedifference L′a between the center 558 of rotation of the disk and thetrue center 557 of the disk is calculated by referring to the equationas “L′a=f(θa, θb, θc)”. The eccentricity corrector 553b corrects therotational angle signal of the rotational angle sensor 17a in responseto the calculated eccentricity (offset or difference). Thereby, it ispossible to compensate for the eccentricity. Thus, there is an advantagesuch that the angular resolution can be increased to an accuracy of onedegree or less, and that the accuracy of detection of a illegal disk canbe improved.

A flowchart of FIG. 247 is a modification of the flowchart of FIG. 240.The flowchart of FIG. 247 is designed so that an address judged to beillegal is accessed and reproduced twice or more, and a check is done toprevent wrong judgment (see steps 551t, 551u, and 551v). The flowchartof FIG. 247 is similar to the flowchart of FIG. 240 except for thefollowing points. If a judgment of being not within an allowable rangeis done at a step 551r, an address An is accessed twice or more at astep 551t. Then, at a step 551u, detection is given of a zone number Z′ndenoting the relative angle with respect to the address An. At a step551v, a check is made twice or more as to whether or not it is withinthe allowable range. It it is yes, the current disk is judged to be alegal (legitimate) disk and advance to a step 551s is done. If it is no,the current disk is judged to be an illegal disk and advance to steps471u and 471s is done to prevent start of a program.

The prevention of wrong judgement is also enabled by using a statisticalprocess as follows. As shown in FIG. 245(a), a legal (legitimate)original disk has frequency distributions as in a graph 1 regardingangle-address, angle-tracking direction, address-tracking direction,angle-pit depth, and address-pit depth. As in g graph 2, specified datais selected. In the case where reproduction is done by a player, data ofsample addresses which can be easily discriminated is selected. As shownn FIG. 245(b), reproduction is done on a formed disk, and a signalportion outside an allowable range is found out as denoted in black in agraph 3. An abnormal value outside the allowable range is deleted from alist as shown in a graph 4. The drawing shows the frequency distributionof angle-address arrangement (layout). A similar advantage is availablein the case of a distribution of pit depth or a distribution ofaddress-tracking amount. In this way, it is possible to delete a copyprotecting signal portion from the list. It should be noted that thedeleted copy protecting signal portion tends to be erroneously judged tobe wrong since discrimination thereof is difficult. Accordingly, therate of occurrence of wrong judgment is reduced during reproduction bythe reproducing player. The probability of errors can be further reducedby accessing an address which has been judged to be illegal twice ormore.

In the case of an illegally copied original disk, as shown in FIG.245(c), the original disk is formed by reading out addresses of a formeddisk. Thus, as in a graph 5, there occurs a CP (copy protection) signaldistributed in a range where a probability is constant. In this case, adisk physical arrangement (layout) table can not be changed, andselection of data can riot be executed as in the graph 2. Therefore,data close to the allowable range limit or a CP signal exceeding theallowable range is present in the physical arrangement (layout) of theillegal original disk. An optical disk formed from such an illegaloriginal disk by shaping press has an additional error due to a shapingvariation, and a distribution is in a condition as in a graph 6. Thus,there is generated a physical arrangement signal 552b which exceeds theallowable range as denoted in black. The physical arrangement signal552b peculiar to the illegal disk is detected by the disk check program,and the detection thereof stops the program and prevents the use of thecopied disk. In this way, the temporal distribution of the CP signalrelated to angle-address is dispersed in a small range by the shapingpress. With reference to FIG. 250(b), a pit depth is greatly varied inresponse to cutting and shaping conditions. Since accurate control ofthe pit depth tends to be difficult, the yield of illegally copied disksis remarkably reduced. Thus, in the case of a pit depth, a stronger copyprotection can be provided.

With reference to FIG. 246 and FIG. 249, a recording and reproducingapparatus 1 includes a disk physical arrangement detector 556 havingthree detectors, that is, an angular position detector 553, a trackingvariation detector 554, and a pit depth detector 555. The detectorsdetect angular position information Z′n, a tracking variation T′n, and apit depth D′n, and output detection signals representative thereof.Confirmation as to agreement with a signal A′n of an address detector557 provides correspondence data of A′n-Z′n, A′n-T′n, and A′n-D′n, orZ′n-T′n, Z′n-D′n, and T′n-D′n. A secret code decoder 534 outputs datacorresponding to a legal (legitimate) disk, and the output data isstored into a reference disk physical arrangement (layout) table 532. Ina collating portion 535, the previously indicated correspondence data iscollated with data An, Zn, Tn, and Dn in the table 532. If the currentdisk is judged to be an illegal disk as a result of the collation, anoutput/operation stopping device, 536 stops operation of the program.

A flowchart of FIG. 247 is similar to the flowchart of FIG. 240 exceptfor the following points. A disk check program includes a step 551w atwhich a check is made as to whether or not a CP secret key decodingprogram is modified, that is, whether or not a first secret code decoder534a having a one-direction function calculator 534c of RSA or othersfor decoding a secret code in the reference physical arrangement(layout) table 532 in a secret code decoder 534 of FIG. 249 is changed.It it is yes, operation is stopped. Thus, even if the first secret codedecoder 534a is illegally replaced by another, operation is stopped.Accordingly, there is an advantage such that the safety of the secretcode can be higher while the copy protection can be better. At a step551f, the position of a given address is measured in the case of anangular position. In addition, measurement is given of the condition ofdistribution of the error amount with respect to the reference angle inthe reference physical arrangement (layout) table 532 of the zonenumber. A definition is now made such that “m=0” means the absence of azone having an error and “m=±n” means the presence of n zones havingerrors. At a step 551g, setting is done as “m=−1”. At a step 551h,setting is done as “m=m+1”. At a step 551i, a check is made as towhether m members of the measured angular zones Z′n have errors. If itis no, return to the step 551h is done. If it is yes, addition to theerror distribution list of Z′n is done at a step 551j. Thus, tables ofdistributions of errors are sequentially made. If “m=last” is detectedat a step 551k, advance to a step 471n is done. Otherwise, return to thestep 551h is done. In this way, measurement is made as to the conditionsof the distributions of errors from the references with respect to theangular position of the given address, the tacking variation, the pitdepth, and the angle/address position shown in FIG. 249.

A step 551m in the disk check program 471t is a properness judgingprogram which provides the following process. A step 551 executesreadout by decoding a secret key of a maximum tolerance (allowablerange) Pn(m) with respect to the error amount m from the reference valueof the angular arrangement Z′n of the address n which has been made intoa secret code and recorded on the optical recording layer or themagnetic layer. Then, a check is made on the reference physicalarrangement (layout) table 532a and the error distribution table 556a ofFIG. 251 which is made according to the distribution measuring programfor the physical position in the step 551f, and judgment is doneregarding whether the current disk is legal or illegal. At a step 551p,setting is done as “m=O”. At a step 551q, setting is done as “m=m=1”. Ata step 551r, a check is made as to a condition of being, within thetolerance (allowable range). Specifically, the check regarding thecondition of being within the tolerance (allowable range) is executed bydeciding whether or not the number of Z′n is smaller than the tolerancePn(m) of FIG. 251. If it is no, advance to the step 551f is done so thatthe present address is accessed again. When this access results in anegative state, the current disk is judged to be illegal. If it is yesat the step 551r, advance to a step 551s is done. When “m=last” isdetected at the step 551s, advance to a step 471p is done. Otherwise,return to the step 551q is done. In this way, measurement is made as tothe distribution of errors of Z′n relative to zn, and the statisticalprocess is executed. According to the statistical process, the currentdisk is judged to be a legal (legitimate) disk under the condition ofbeing within the tolerance, and the current disk, is judged to be anillegal disk under the condition of being outside the tolerance. Thus,there is an advantage such that the discrimination between a legal(legitimate) disk and an illegal disk can be executed more accurately.

The flowchart of FIG. 247 includes a step 551a at which a randomderiving device 582 such as a random number generator 583 of FIG. 249 iscontrolled to feed a partial selection signal to a magnetic reproductioncircuit 30 or a secret code decoder 534 so that an optical track or amagnetic track storing a secret code is selected from among all tracksand is accessed and subjected to reproduction. Thus, access to a portionof the whole amount of secret code data suffices, and there is anadvantage such that a mechanical access time is shortened and a copychecking time is shortened. The random deriving device 582 feeds aselection signal to the secret code decoder 534, and a portion of thereproduced secret code data is decoded. This partial selection processprovides an advantage such that a secret code decoding time isshortened. The random number generator 584 enables such a function that,with respect to only a necessary minimum amount of samples for eachtime, sample data which varies time to time is subjected to disk check.This function enhances the copy protection. The addition of the randomderiving device 582 remarkably shortens the disk checking time withoutreducing the copy protection.

As shown in FIG. 249, the disk physical arrangement detector in therecording and reproducing apparatus 1 has two detectors, that is, atracking amount detector 554 and a pit depth detector 555, in additionto the angular position detector 553. A tracking amount sensor 24a canbe a tracking error detection circuit which is able to measure wobblingof a tracking control portion 24 of an optical head 6. The trackingamount detector 554 receives a tracking amount Tn of an address n fromthe tracking amount sensor 24a, and measures temporal agreement betweenthe tracking amount and other detection signals A′n, Z′n, and D′n andoutputs a result of the measurement to the collating portion 535 as asignal T′n.

In the case of a legal (legitimate) disk of FIG. 253(a), thephysical-position 539a of an address A1 is subjected to modulation suchas wobbling in the tracking direction during the manufacture of anoriginal disk. Therefore, tracking is offset in a direction toward anouter edge. This condition is defined as “T1=+1”, and the relation“T2=−1” appears at the physical position 539b of an address A2. Thisinformation can be detected during or after the manufacture of anoriginal disk, and a reference physical arrangement (layout) table 532is made which is converted into a secret code before being recorded onthe medium 2.

In the case of an illegally copied medium 2 of FIG. 253(b), a normaltracking variation fails to be added. Even if a tracking variation isadded, tracking variations T′1 and T′2 of addresses A1 and A2 in a sameangular zone Z1 are in a state of O1+1 as shown in the drawing. Thus, ameasured disk physical arrangement (layout) table 556 differs from thereference physical arrangement (layout) table 532 corresponding to alegal (legitimate) disk. This fact is detected by the collating portion535 in the disk check portion 533 of FIG. 249, and the output/operationstopping device 536 stops the outputting of the program, the operationof the program, or the decoding of the secret code of an applicationprogram by a second secret code decoder 534b. In addition, the display16 is controlled to indicate “illegally copied disk”. In FIG. 249, thedisk check program is made into the secret code, and it is difficult tochange the disk check program. This is advantageous in the copyprotection.

As shown in FIG. 249, the optical reproduced signal is fed from theoptical head 6 to an amplitude detector 555a in the pit depth detector555. The information detected by the amplitude detector 555a relates toa variation in the degree of modulation or an amplitude such as anenvelope. The amplitude detector 555a can be a multiple value levelslicer. The amplitude detector 555a detects a pit depth in response toan amplitude variation, and outputs a detection output signal D′n to thecollating portion 535. In the collating portion 535, the detectedinformation D′n is collated with data in the reference physicalarrangement (layout) table 532. If the detected information D′n differsfrom the reference data, the copy protecting process is started.

In this way, as shown in FIGS. 254(a), 254(b), 254(c), and 254(d), fourparameters being an address An, an angle Zn, a tracking variation amountTn, and a pit depth Dn are checked with respect to physical arrangements539a, 539b, and 539c composing one sample point. This is advantageous inenhancing the copy protection.

As shown in FIG. 269, at a step 584a, for example, 1000 pit groups arerecorded on a same original disk with 1000 different recordingconditions related to a recording output and a pulse width. In thiscase, at a step 584b, pit groups are made which meet 5 differentconditions when the yield corresponds to, for example, 1/200. At a step564c, the physical arrangements of these good pit groups are found outby monitoring the original disk with laser light. At a step 584d, aphysical arrangement (layout) table corresponding to the good pit groupsis made. At a step 584e, the physical arrangement (layout), table ismade into a secret code. In the case of optical recording which isdetected at a step 584f, the secret code is recorded on a secondphotosensitive portion 572a of the original disk at a step 584g. At astep 584h, plastic is injected into the original disk to form an opticaldisk. At a step 584i, a reflecting film is made. If a requirement for amagnetic layer is not detected at a step 584j, the optical disk iscompleted. Otherwise, at a step 584k, a magnetic record portion is made.At a step 584m, the secret code is recorded on the magnetic recordportion. As a result, the optical disk is completed. Since the pit depthis measured after the original disk is formed and the arrangement(layout) table is made into the secret code before being recorded, it ispossible to increase the yield to about 100% during the manufacture ofthe original disk.

In the case of an illegally copied disk of FIG. 250(a), pits 561a-561fare equal in depth. In the case of a legal (legitimate) disk of FIG.250(b), pits 560c, 560d, and 560e have small depths. Accordingly, asshown in FIG. 250(c), corresponding reproduction pulses 562c, 562d, and562e have small peak values. An effective output signal such as shown inFIG. 250(f) appears with a reference slice level S0 in the multiplelevel slicer 555b. On the other hand, as shown in FIG. 250(d), noeffective output signal appears with a detection slice level S1. Thus,AND operation is executed between the inverted value of S1 and S0, andthereby copy protection signals 563c, 563d, and 563e are generated onlyin the case of a legal (legitimate) disk as shown in FIG. 250(g). In thecase of an illegal disk, since the output of the detecting slice levelS1 is consecutively “1”, any copy protection signal is not outputted.Accordingly, a copied disk is detected. A similar advantage is availablealso in the case where, as shown in FIG. 250(e), the amplitude amountdetector 555a detects a reduction in the modulation rate or a reductionin the amplitude of the envelope of the optical output waveform, andthereby an inverted code signal with respect to S1 is generated.

It is clear from FIG. 256 that, in an original disk making apparatus fora normal CD or MD, an angle control function is absent and thus diskcheck in an angular direction, that is, “A”, is effective. In anoriginal disk making apparatus for a ROM, a CD, an MD, or a laser disk,a device for control in a tracking direction or in wobbling is absentand thus a variation in the tracking direction, that is. “B”, iseffective. The combination “A+B” provides reliable copy protection, andis compatible with conventional IC's for a CD and an MD.

FIG. 257 shows a mastering apparatus 529 which is similar to themastering apparatus of FIG. 234 except for the following points. Asshown in FIG. 257, a system controller has a tracking modulation signalgenerator 564 which feeds a tracking controller 24 with a modulationsignal. Thus, tracking is done with approximately a constant radius r0based on a reference track pitch 24a. Modulation such as wobbling iscarried out in the range of r0+dr with respect to the track radius r0.Therefore, as shown in FIGS. 253(a) and 253(b), a zigzag track is formedon, an original disk 572. Information of the tracking variation amountif fed to a tracking variation information portion 32g in a positionalinformation input portion 32b. A copy protection signal generator 565makes a reference physical arrangement (layout) table 532 which is atable of an address An, an, angle Zn, a tracking variation amount Tn,and a pit depth Dn. The reference physical arrangement (layout) table532 has been described with reference to FIG. 246. A secret code encoder537 encodes the table into a secret code. The secret code is recorded ona second original disk 572a provided on an outer portion of an originaldisk such as shown in FIG. 265 and FIGS. 266(a) and 266(b), or isrecorded on an original disk at a second region provided on an outerportion such as shown in FIG. 267 and FIGS. 268(a) and 268(b). It ispossible to independently add modulation Dn in a pit depth direction.The system controller 10 in FIG. 257 has an optical output modulationsignal generator 566, and the amplitude of a laser output of an outputmodulator 567 in an optical record portion 37b is varied as shown inFIG. 263(b) or a pulse width or a pulse interval is modulated by a pulsewidth modulator 568 while the amplitude is held constant. Thereby, theeffective value of the laser output can be varied. Thus, as shown inFIG. 263(c), a photosensitive portion 573 of the original disk 572 isformed with a portion 574 which is different in depth. The original diskis etched, and pits 560a-560e having different depths are formed asshown in FIG. 263(d). For example, pits 560a, 560c, and 560d havegreater depths corresponding to about λ/4, while pits 560b and 560e havesmaller depths corresponding to about λ6. The original disk 572 issubjected to metal plating such as nickel plating, and thereby theoriginal disk 572 is made into a metal original disk 575 such as shownin FIG. 263(e). Then, plastic molding is executed to form a molded disk576.

In this way, the original disk is formed with pits while the amplitudeof the laser output is varied. In the case of such a disk, as shown in awaveform (5) of FIG. 264, the peak value of a reproduced output signalis, equal to a reduced value. Thus, when a level slicer executes aslicing process with a given slice level, a pulse width is detected asbeing narrower than that in a pit of a greater depth so that a correctdigital output signal is not available. To solve this problem, a pulsewidth adjuster 569 generates pulses of wider widths T+ΔT such as shownin a waveform (2) of FIG. 264 in response to an original signal having aperiod T such as shown in a waveform (1) of FIG. 264. Thus, as shown ina waveform (6) of FIG. 264, the digital signal is corrected. In theabsence of this correction, a sliced digital output signal narrower inwidth than the original signal appears as shown in a waveform (7) ofFIG. 264 so that a wrong digital signal is outputted.

In this way, the pit depth is modulated by the optical output modulator567. The pit depth information Dn is fed from the optical outputmodulation signal generator 566 to the pit depth information portion32h. The copy protection signal generator 565 makes the referencephysical arrangement (layout) table 532 which is a table of thepreviously-indicated parameters An, Zn, Tn, and Dn. The secret codeencoder 537 encodes the table into the secret code, which is recorded onthe magnetic recording layer.

According to an alternative way, as in steps of FIG. 267, after aphotosensitive portion 577 provided on an outer portion of an originaldisk has been made, pit depths and others are measured (see a step 5)and a physical arrangement (layout) table is generated. The table ismade into a secret code. At a step 6, the secret code is recorded on asecond photosensitive portion 577. Thereby, as shown in steps 7, 8, and9, a program software and the physical arrangement (layout) table 532can be recorded on a single original disk. In the case where differentID numbers are not recorded on respective disks, a magnetic layer may beomitted. In this case, copy protection can be attained only by anoptical record portion.

FIG. 268(a) is a top view of an original disk. FIG. 268(b) is asectional view of the original disk. As shown in FIG. 265 and FIGS.266(a) and 266(b), two original disks may be bonded together.

As shown in FIG. 257, a communication interface 578 serves forcommunication with an external device. As shown in FIG. 262, a softwarecopyright holder has an external secret code encoder 579. The externalsecret code encoder 579 encodes a physical arrangement (layout) tableinto a secret code in response to a first secret code, key 32d. Thesecret code is transmitted from the external secret code encoder 579 tothe mastering apparatus 529 in an optical disk maker via a secondcommunication interface 578a, a communication line, and thecommunication interface 578. Since the first secret code key 32d is notgiven to the optical disk maker from the software copyright holder, thesafety of the secret code is high.

In the case where a combination of a pulse width and a pit depth isintended to be changed as shown in FIG. 255, the amplitude of the laseroutput and the pulse width are changed for each pulse. In this case,optimal conditions of the laser output and the pulse width vary frompulse to pulse. Accordingly, as shown in FIG. 255, n differentconditions of the combination are made while the value of the laseroutput and the pulse width are varied in consideration of a gammacharacteristic. For example, several hundreds of combinations of laseroutputs are made, and original disks are formed under several hundredsof different conditions. In this case, several original disks have pitsof optimal depths. When a signal is reproduced from such a good originaldisk, the reproduced signal reaches the reference voltage S0 but notreach the detection voltage S1 as shown by waveforms 581a and 581c inthe portion (3) of FIG. 255.

This invention uses a way of making optimal pits during the manufactureof an original disk. Specifically, as shown in FIGS. 263(a)-263(e),several hundreds “n” of bit groups 580a-580d are provided, and recordingis done under “n” different laser output conditions. In this case,several pit groups among the “n” pit groups meet required conditions ofpit depths, pit shapes, and pulse widths. As shown in FIG. 248, thephysical arrangement (layout) table 532 of such a good pit group 580c ismade into a secret code, and the secret code is recorded on the magneticrecord portion of the disk 2. The secret code may be recorded on theoptical record portion of the original disk 572 in the secondphotosensitive portion or the second original disk shown in FIGS. 266(a)and 266(b) and FIGS. 268(a) and 268(b). In this way, the disk isobtained which has the copy protection using the pit depth.

A similar advantage is provided in the case where a record type opticaldisk such as a partial ROM is used, and a physical arrangement (layout)table is made into a secret code, which is recorded on the recordinglayer of the optical RAM. A plurality of the disk check programs may beplaced in a program installing routine 584d, a printing routine 584e, asaving routine 584f, and other routines of a program 586 in anapplication, software (see FIG. 270) respectively. This design enhancesthe copy protection.

DESCRIPTION OF THE EIGHTEENTH PREFERRED EMBODIMENT

An eighteenth embodiment of this invention realizes a copy guardfunction which can be applied to the case where a software such as an OSis installed into a given number of machines or personal computers. FIG.149 shows an arrangement of the eighteenth embodiment which is similarto the arrangement of FIG. 147 except for design changes indicatedhereinafter.

An optical mark portion 387 or a high Hc portion 401 of a disk storesdata of the maximum number of personal computers into which informationis permitted to be installed from the disk The data is formed as data ofa disk ID number (OPT) or a disk ID number (Mag) for a key managementtable. For example, the data represents “ID=204312001. N1=5, N2=3”. Thismeans that the disk ID number is “204312001”. Additionally, this meansthat the maximum number of personal computers into which a first programis permitted to be installed is equal to 5, and that the maximum numberof personal computers into which a second program is permitted to beinstalled is equal to 3. As shown in the drawing, in the case where aprogram 1 is installed into a first personal computer 408 identified as“xxxx11”, a key unlocking decoder 406 outputs data since five tables ofthe program 1 remain. The output data enables a program such as an OS tobe installed into a hard disk 409 of the first personal computer 408 viaan external interface 14. At this time, the data of the ID number“xxxx11” of the personal computer 408 is fed to a CD ROM drive 1a. TheID data is stored into an “n=1” position of the program 1 in the keymanagement table 404, and is then recorded on a magnetic track 67 of theCD ROM.

In the case where the program such as the OS is intended to be installedfrom the CD ROM 2a into a second personal computer 408a identified as“xxxx23”, a check is made on the key management table 404. As a resultof the check, it is known that four machines remain into which theprogram is permitted to be installed. Thus, the installing process isstarted and executed. The data of the ID number “xxxx23” of the personalcomputer 408a is stored into an “n=2” column in the program 1 in the keymanagement table 404. In such a way, the program such as the OS can beinstalled into at most five personal computers. In the case where theprogram such as the OS is intended to be installed into a sixth personalcomputer, there is no unoccupied column in the program 1 so that an IDnumber of the sixth personal computer can not be recorded. Thus, theprogram such as the OS is inhibited from being installed into the sixthpersonal computer. In this way, illegal copy of the program such as theOS is prevented. If the program such as the OS in one of the firstpersonal computer to the fifth personal computer breaks, the programsuch as the OS can be freely installed thereinto since the ID number ofthat personal computer has been already registered. As previouslydescribed, the disk ID number is recorded into the high Hc portion 401and the optical mark 387 as two types of data. This design causes morework and cost to be necessary in copying a disk, and thus enhances thecopy guard function.

A programmed operation sequence for executing the method of thisinvention will now be described with reference to FIG. 150. At a step410a, a command of installing a program having a number N is issued. Ata step 410b, an ID number of a personal computer is read out. Forexample, the ID number is “xxxx11”. Then, a CD ROM 2a is set in a CD ROMdrive 1a. At a step 410c, magnetic data is fed to a memory of thepersonal computer 408 and a key management table 404 is made. At a step410e, a machine ID number registered in a column of the program havingthe number N in the table 404 is readout. At a step 410f, a check ismade as to whether the readout ID number is equal to the ID number ofthe personal computer into which the program is intended to beinstalled. If it is yes, an advance to a step 410q is done. If it is no,a check is made at a step 410g as to whether an unoccupied column (area)for registering the machine ID number is present. Specifically, a checkis made as to how many personal computers remain into which the programis permitted to be installed. If it is no, an advance to a step 410n sothat the program is prevented from being installed. Then, operationstops at a step 410p. On the other hand, if it is yes, the ID number ofthe personal computer into which the program is intended to be installedis registered in the table 404. As a result, a reduction occurs in thenumber of remaining personal computers into which the program ispermitted to be installed. At a step 410i, the machine ID number isrecorded into the magnetic track 67 by the magnetic head. At a step 410jan installing process is started. If the installing process succeeds ata step 410k, the operation stops at the step 410p. If the installingprocess fails, the ID number of the personal computer into which theprogram is intended to be installed is deleted from the magnetic track.Then, the operation stops at the step 410p.

DESCRIPTION OF THE NINETEENTH PREFERRED EMBODIMENT

A ninth embodiment of this invention relates to an interface between apersonal computer and a CD ROM drive. As shown in FIG. 151, a personalcomputer 408 has a software portion 411 containing an applicationprogram 412 such as a word processing software. A Cornell portion 414manages a system. The application transmits and receives information toand from the Cornell portion 414 via a shell portion 413. The Cornellportion 414 has an operating system (OS) 415 in a narrow sense, and aninput/output control system 416. The input/output control system 416includes a device driver 417 for the inputting and outputting of signalsfrom and to devices such as a hard disk. As shown in the drawing, A, B,C, and D drivers 418a, 418b, 418c, and 418d are logically defined asexternal storage units. The personal computer is physically connected tointerfaces 14 and 424 of external storage units such as an HDD 409, a CDROM 2a, and an FDD 426 via an interface 420 such as an SCSI and a BIOS419 composed of a hardware including a software such as information in aROM IC. The personal computer transmits and receives data to and fromthe interfaces 14 and 424.

In the case of a drive 1a for a CD ROM which has a magnetic recordingportion of this invention, two drivers, that is, the A driver 418a andthe B driver 418b are defined in the input/output control system 416.The A driver functions to reproduce data of a logically defined opticalrecord file 421 via the interface 14 in the CD ROM drive 1a. The Adriver does not operate for recording. Specifically, an opticalreproducing portion 7 reads out exclusive playback data from an opticalrecording layer 4 in the optical disk, and the readout data istransmitted to the personal computer 408 via the A driver. The B driverfunctions to record and reproduce data into and from a logically definedmagnetic record file 422. Specifically, a magnetic recording andreproducing portion 9 records and reproduces data into and from themagnetic recording layer 3 of the optical disk 2. The magnetic recordingand reproducing portion 9 transmits and receives data to and from thepersonal computer 408 via the B driver 418b in the device driver 417.

In this embodiment, the two drivers 418a and 418b are defined withrespect to the single drive 1a for a CD ROM having a RAM. According tothis design, provided that the OS 415 executes multiple tasks, therecording and reproduction of the magnetic file 422 can be executedwhile the personal computer 408 reproduces the optical record file 421.Thus, a process of inputting and outputting the files can be performedat a higher speed than the speed in the case where only a single drive418 is present. This advantage is remarkable when a virtual file isused.

Methods of executing the above-mentioned simultaneous processing will bedescribed. A first method is designed as follows. FIG. 152 shows anoptical address table 433 and a magnetic data table 434 of a CD ROM 2ahaving a RAM. In the case of a CD ROM, a write inhibiting flag is activefor all the data in the optical address table 440. As long as specialdesignation is absent, all the data in the magnetic address table 441can be rewritten. A CD ROM drive 1a previously transfers data which ishigh in use frequency, to a drive memory 34a upon the insertion of theCD ROM 2a. Accordingly, the addresses of necessary data in the magneticaddress table 441 are arranged according to the order of the usefrequencies thereof as magnetic data having a physical address of, forexample, “00”. When the disk is inserted into the device, the magneticdata at the address “00” is read out and is transferred to the drivememory 34a in an arrangement according to the order of necessity. Thedrive memory 34a includes an IC memory. This design makes it sufficientthat, during the recording and reproduction of magnetic data into andfrom the CD ROM, the recording and reproduction are executed only byaccessing the data in the IC memory 34a. Thus, in the case where thesimultaneous processing is executed by time-division processing in a CPUof a system controller 10, data reading and writing from and into themagnetic file 422 in the drive memory 34a can be performed while anoptical reproducing section 7 reproduces optical data. Since it issufficient that the recording and reproduction is executed only once onthe magnetic recording layer 3 of the CD ROM 2a, the recording surfacethereof is less injured. Even when a power supply to the CD ROM drive 1ais turned off, the contents of the drive memory 34a is backed up by amemory backup portion 433. Only when the CD ROM 2a is ejected from thedevice, changed magnetic record data in the drive memory 34a is selectedand is recorded into the magnetic recording layer 3 regardless ofwhether the power supply is on or off. Thus, recording into the magneticrecording layer 3 is done only once during the interval between theinsertion of the disk to the ejection of the disk. Therefore, a longlife of the disk is enabled. The files are processed simultaneously orin parallel in this way, so that a higher data transfer speed isattained. The data in the drive memory 34a is backed up by the memorybackup portion 433 even when the power supply to the CD ROM drive 1a isturned off. Thus, in the case where the power supply is turned on again,it is unnecessary to read out the magnetic data from the CD ROM as longas the CD ROM has not been replaced.

A data compressing/expanding portion 435 of FIG. 1 may be provided inthe system controller 10 of the CD ROM drive 1a. This design increasesthe substantive capacity of the magnetic file 422.

Next, a description will be given of the case where the CD ROM drive ofthis invention is handled as a single drive. The operation in this caseis similar to that in the case of two drives except for the followingpoints.

As shown in FIG. 153, a CD ROM having a RAM according to this inventioncan be handled as one drive such as an A drive 418 in an input/outputcontrol system 416 of a personal computer 408. In this case, even asingle-task OS can read and write data from and into a drive 1a for theCD ROM having the RAM. According to a file design, as shown in FIGS.154(a) and 154(b), successive addresses are assigned to an optical file421 and a magnetic file 422. In addition, an optical data table 440 anda magnetic data table 441 are handled as a single file. For example, asshown in the drawing, addresses up to a logic address “01251” areassigned to data of the CD ROM, and active write inhibiting flags areapplied to all of them. Addresses starting from the logic address“01252” are assigned to magnetic data, and active write enabling flagsare applied thereto.

The personal computer is enabled to handle the CD ROM having the RAM asa single memory disk. The optical data can be reproduced. The magneticdata can be recorded and reproduced. The address of magnetic data whichis high in use frequency is recorded as the logic address “01252”. Thus,by transferring the data in the magnetic recording layer 3, whichcorresponds to this address, to the magnetic file 422 of the drivememory 34a via the magnetic recording and reproducing section 9 and thedata compressing/expanding section 435 after the insertion of the CD ROM2a into the device as shown in the drawing, it is hardly necessary tophysically read out the data from the magnetic recording layer 3 in alater period. The recording and reproduction of the magnetic data arevirtually performed by rewriting the data in the drive memory 34acomposed of the IC memory. The amount of the magnetic data is equal to asmall value, for example, 32 KB, so that all the magnetic data can bestored in a small-capacity IC memory. This design enables a longer lifeof the disk and higher speeds of access, and data inputting andoutputting processes. As previously described, the magnetic data isphysically recorded only when the disk is ejected from the device. Theone-drive system can be simple in structure.

A method of effectively executing the reproduction of data from themagnetic recording layer 3 and the reproduction of data from the opticalrecording layer 4. To prevent a reduction in data transmission rate of aCD ROM, it is desirable that the reproduction on the magnetic recordinglayer is done while the reproduction on the optical recording layer isbeing executed. In addition, it is important to shorten a start-up timeupon the insertion of a CD ROM into a drive. A file arrangementaccording to this embodiment is designed as follows. As shown in FIGS.154(a) and 154(b), a CD ROM 2a having a magnetic recording layer has anoptical file 421 and a small-capacity magnetic file 422 provided withphysical and optical addresses and magnetic-addresses other than anoptical address table 440 respectively. As shown in FIG. 155, magneticdrives 67a, 67b, 67c, 67d, 67e, and 67f are located at back sides of theoptical addresses A, B, C, D, E, and F, which correspond to the magneticaddresses a, b, c, d, e, and f respectively. This correspondencerelation is recorded in a magnetic TOC area at a magnetic address of 00together with frequency management data. The system controller 10 ofFIG. 153 has a 1-address link table 443 which informs the drive memory34a of the physical positions of the optical address and the magneticaddress. As shown in FIG. 154(b), the contents thereof have two addresslink recorded information.

A specific method of simultaneously performing the reproduction of themagnetic data and the reproduction of the optical data will now beexplained. In the case where a CD ROM is inserted into the drive tostart up only a necessary program the reproduction of only necessaryoptical data is executed. It is good that only magnetic data necessaryfor starting the program is recorded in the magnetic track on the backside of the optical track storing the necessarily reproduced data. Thenecessary magnetic data is, for example, personal point data andpersonal progress data related to a game software.

The operation according to this method will now be described withreference to FIG. 156. At a step 444a, an initial value “m=0” is set. Ata step 444b, an incrementing process is done by referring to a statement“m=m+1”. At a step 444c, a check is made as to whether the number m isequal to a final value. If it is yes, a jump to a step 444m is done. Ifit is no, an advance to a step 444d is done so that optical data in anm-th optical address A(m) is reproduced. Then, at a step 444e, anentrance into a subroutine is done which serves to find an opticaladdress, among optical addresses in the optical track corresponding tothe magnetic track, which is close to the optical address A(m). In thesubroutine, at a step 444f, setting “n=0” is done. At a step 444g, anincrementing process is executed by referring to a -statement “n=n+1”.At a step 444w a check is made as to whether the number n is equal to afinal value. If it is yes, a jump to the step 444m is done. If it isyes, an optical address M(n) at the back side of the n-th magneticaddress is read out from the address link table 443 at a step 444h. At astep 444i, a checking process of, for example, “M(n)+10” is done tocheck whether the optical address is close thereto. If it is no, areturn to the step 444g is done to check a next optical address. If itis yes, the magnetic head is lowered onto the magnetic recording layer 3at a step 444j so that the data in the magnetic address n is reproducedand the optical traverse is fixed. At a step 444k, a check-is made as towhether the reproduction of the magnetic data has been completed. If itis no, the step 444j is executed again. If it is yes, a return to thestep 444b is done so that the number m is incremented by one. Theabove-mentioned processes are repeated. Here, if the number m reaches anend value (a completed value), a jump to a step 444m is done to checkwhether the reproduction on the magnetic track containing the datanecessary for starting the program has been completed in conjunctionwith a step 444n. If it has been completed, a jump to a step 444v isdone. If it has not yet been completed, the entrance into a subroutine444p for the reproduction on n0 magnetic tracks is performed toreproduce the remaining magnetic data. In this subroutine, setting “n=0”is done at a step 444q, and setting “n=n+1” is done at a step 444r. At astep 444s, a check is made as to whether the number n reaches acompleted value. If it is yes, a jump to the step 444v is done. If it isno, the optical address corresponding to the n-th magnetic address isaccessed. The magnetic data is reproduced at a step 444u, and a returnto the step 444r is done to execute the setting “n=n+1”. As long as thecompletion has not yet been reached, the similar processes are repeated.If the completion has been attained, a jump to the step 444v is done sothat the work of reproducing the data for starting the program iscompleted.

According to this design, the magnetic data necessary for starting theprogram is recorded on the magnetic track at the back side of theoptical track of the optical data. Thereby, there is an advantage suchthat a time for starting the program can be shorted. In this case, asshown in FIGS. 154(a) and 154(b), the selection of the magnetic trackson the back sides of the optical tracks means that the magnetic tracksare not always arranged at equal intervals. The use of the variablepitch magnetic tracks of this invention realizes the shortening of thetime for starting the program.

As shown in FIG. 154(a) and 154(b), the optical addresses of the opticaltracks at the back sides of the magnetic tracks 01, 02, . . . into themagnetic TOC area, and magnetic tracks at a free pitch can be realized.The magnetic tracks are arranged according to the use frequency, andthereby frequency management data can be omitted and the substantivecapacity can be larger.

DESCRIPTION OF THE TWENTIETH PREFERRED EMBODIMENT

A twentieth embodiment of this invention relates to a method ofcorrecting bugs in a program in a CD ROM software by using a CD ROM 1a.As shown in FIG. 157(b), a bug correcting program 455 is recorded in anoptical file 421 in the CD ROM 1a having a capacity of 540 MB. A programsuch as an OS is also stored in the remaining part thereof as a ROMdata. A magnetic file 422 has a capacity of about 32 KB, which containsonly bug correcting data. As shown in FIG. 157(b), correction data,correction contents, and optical addresses of optical ROM data to becorrected are contained therein. As shown in FIG. 157(c), only a givenfile such as an OS which has bugs is transferred to a memory 34, andcorrection-resultant data 448 is generated in response to the bugcorrecting program 447 and the bug correcting data 446.

An operation sequence will now be described with reference to FIG.157(a). When the given file having the bugs is read out at a step 445a,the whole of the given file is transferred to the memory 34. At a step445b, setting “N=0” is done. At a step 445c, the number N isincremented. At a step 445d, N-th bug correcting data in the given fileis read out. At a step 445e, a check is made as to whether thecorrection is of the type without changing the address. If it is yes,the data is corrected at a step 445f. If it is no, the line is deletedat a step 445h. At a step 445j, the logic address of the optical file ischanged. Then, an advance to a step 445k is done. At the step 445k, acheck is made as to whether a line is added. If it is no, an advance toa step 445p is done. If it is yes, the addition of the line is executedat steps 445m and 445n so that the logic address of the optical file ischanged. Then, an advance to a step 445p is done. At the step 445p, acheck is made as to whether other processing is present. If it is no, anadvance to a step 445r is done. If it is yes, the other processing isexecuted at a step 445q. At the step 445r, a check is made as to whetherthe number N reaches M, that is, whether the correction has beencompleted. At a step 445s, the correction is completed. The given filewhich has been corrected is outputted.

In this embodiment, the correcting program is previously recorded intothe optical ROM portion, and the correcting data is recorded into themagnetic file upon the shipment of the recording medium (the opticaldisk). This design is advantageous in that the correction of bugs in theOS or others can be executed after the manufacture of the optical disk.The correcting program is recorded into the optical ROM portion whileonly the correcting data is recorded into the magnetic file 422. Thisdesign enables the recording of a relatively large amount of thecorrecting data.

DESCRIPTION OF THE TWENTY-FIRST PREFERRED EMBODIMENT

A twenty-first embodiment of this invention relates to a method ofcorrecting data bugs in a CD ROM in real time during the readout of afile such as a dictionary. As shown in FIG. 158(b), an optical ROM datacorrecting table 446 is recorded in a magnetic file 422, andcorrection-resultant data corresponding to an optical address isrecorded therein. As shown in FIG. 158(c), data of an optical file 421is corrected in real time in response to a correcting program in theoptical file 421 and the correcting data in the magnetic file 422. Thecorrection-resultant data is outputted as data 448.

An operation sequence will now be described with reference to FIG.158(a). With respect to the file data correcting program 447, a commandof reading out given optical data is received at a step 447a. At a step447b, a number N is set to a starting number of an optical address ofdata to be read out. At a step 447c, the number N is incremented by one.At a step 447d, data at the optical address N is read out. At a step447e, a check is made as to whether the optical address is kl-kM of thecorrecting table 446. If it is no, an advance to a step 447g is done. Ifit is yes, the data at the optical address N is corrected in response tothe correcting table 447f. Then, at the step 447g, a check is made as toall necessary optical data is read out. If it is no, a return to thestep 447c is done. If it is yes, an advance to a step 447h is done tooutput the correction-resultant optical data. Since the data iscorrected and outputted in unit of optical address, this design isadvantageous in that the data can be outputted in real time. In the caseof a dictionary, the magnetic recording layer 3 can be used forrecording data having a high use frequency and marking important data.

DESCRIPTION OF THE TWENTY-SECOND PREFERRED EMBODIMENT

A twenty-second embodiment of this invention relates to a method oflogically increasing the capacity of a magnetic file using a virtualmemory in which a physical large-capacity file in a hard disk 425 islogically present in the magnetic file 422. The arrangement of thisembodiment is similar to the arrangement of FIG. 153 except for designchanges indicated hereinafter.

As shown in FIG. 159, a personal computer 408 corresponding to a machineID=Ap, a CD ROM drive 1a, an HDD 425, corresponding to a disk ID=AH, adisk drive DD corresponding to a disk ID=BH, a replaceable optical disk428 are physically connected via interfaces. A magnetic file 422 can beconnected to a personal computer 408a corresponding to a machine ID=Bpvia a LAN network such as TOPIP, a communication port 432, a networkBIOS 436, a network OS 431, and an application program 412, and also canbe connected to a hard disk 405a corresponding to a disk ID=CD which isdirectly coupled with the personal computer 408a. In this embodiment,virtual large-capacity disks in the magnetic file 422 can be set in thehard disk 425 of the personal computer 408, the replaceable disk 428,and a hard disk 425a, of another personal computer 403a respectively.The virtual disks are denoted by 450, 450a, and 450b respectively. Theuse of the virtual disk 450 virtually increases the capacity of themagnetic file 422 to, for example, 100 MB or 10 GB.

A specific data structure will be described with reference to FIG. 160.The CD ROM 1a has the physically-existing optical file 421, thephysically-existing magnetic file 422, and the logically-defined virtualfile 450. Actual data in the virtual file 450 is stored in the HDD 425,the replaceable disk 428, or the physical file 451 in the HDD 425a. Themagnetic file portion 422 of the CD ROM 1a contains a virtual directoryentry 452 holding directory information such as characters and names ofrespective virtual files, and link information of the physical file 451and the virtual file 450. The virtual directory entry has characteristicdata related to 11 items that is, 1) an address 438 in the magneticfile, 2) a connection program including a command of connection withanother personal computer via the LAN, 3) a machine ID number 454 whichcontains a machine ID number of a drive or a personal computer providedwith the disk storing a physical file 451 containing the actual data, 4)the disk ID number 455 of the disk containing the physical file 451, 5)the name 456 of the virtual file, 6) an expanding item 457, 7) acharacteristic 458 indicating the type of the virtual file, 8) areservation region 459, 9) the time and the date of change of the file,10) a start cluster number 461 indicating the cluster number at whichthe file is started, and 11) a file size 462. The fifth item to theeleventh item are equal to those in directory used by an OS such asMSDOS, and are usually composed of 32 bytes. All the items occupy 48 to64 bytes.

As shown in the magnetic file table 422a, the magnetic file 422 containsa number of virtual directory entries 452 which is equal to the numberof virtual files. FIG. 160 shows only the items 1, 2, 3, 4, 5, and 10.

With respect to the first virtual directory entry 452a. “AN” is in theconnection program number corresponding to the item 2). It is known fromthe sub machine ID number 454 corresponding to the item 3) that the IDnumber of the machine containing the physical address 451 is Ap. Sincethe CD ROM 1a is connected to the CD ROM drive of the personal computercorresponding to the machine ID=Ap, it is unnecessary that theconnection program AN for connecting the LAN is started to access thedisk of another personal computer In the case where the main machine IDnumber 454 corresponds to another personal computer, the connectionprogram AN is started and the connection to the personal computer of theLAN address corresponding to the main machine ID number 454 is providedso that the disk 425a thereof is accessed. Since substantially all thedirectory information is in the link data 452, it is unnecessary toaccess the physical file 451 when the personal computer looks at thedirectory. It is sufficient to access the physical file only when datais read and written from and into the virtual file 450.

In this way, access to the physical file is executed. As shown in thedirectory range table 465, the directory 463 of the physical filecontains sub virtual directory entry 467 of a normal format. This datastores items 5)-11) among the items 1)-11) in the main virtual directoryentry 452. Data of the main disk ID number at the original CD ROM sidehaving the virtual file 450, data of the user ID number 470corresponding to the setting of the virtual file 450, data of a secretnumber 471 for each file, and data of the main machine ID number 472corresponding to the final main personal computer making the virtualfile are added to a sub reservation region 468 corresponding to the item8) in comparison with that in the virtual directory entry 452. The addeddata is used for checking and confirming the relation between thevirtual file 450 and the physical file 451 from the physical file side.If the relation is decided to be in a low degree as a result of thecheck, a permission of writing an OS is not issued. To inhibit normalwriting which does not relate to the virtual file 450, reproductionexclusive code as “01H” is stored in the characteristic 458corresponding to the item 7) in the case of MSDOS. Thus, in general, therecording can not be executed. In the case where data is recorded intothe virtual file 450, information such as the change information 460 andthe CD ROM ID number 469 associated with the virtual file 450 is fed tothe input/output control system of the personal computer. A check ismade as to whether this data agrees with the sub file link data 467. Ifthe result of the check is good, the IOSYS in the Cornell portionpermits the writing into the physical file 451 so that the recording isexecuted. In the case where data is added to “File A”, the directory 463of the physical file 451 is examined and the contents of FAT 466 areadditionally written as FAT 466a so that the additional data in the“File A” is physically recorded into the new data region. In this case,the file size is expanded, and the data of the file size 462 of each ofthe virtual directory entry and the directory entry 467 in the virtualfile and the physical file is written into, for example, “5600 KB”.

In this way, the data of the physical file 451 corresponding to thevirtual file 450 can be recorded and reproduced. Since all the workrelated to the virtual file 450 is performed by the OS, the input/outputOS, and the network OS, the user can handle the apparatus as if thephysical file having a capacity of, for example, 5600 KB, is present inthe magnetic recording layer 3 of the CD ROM 1a.

Physical recording and reproduction of data is enabled by linking thephysical file 451 and the virtual file 450 in response to the data fromthe virtual directory entry 452. Although the capacity of the magneticfile 422 is equal to a small value, that is, 32 KB, in connection withthe CD ROM 1a, 500to 1000 virtual directories 452 can be provided andthus virtual recording and reproduction on 500 to 1000 virtual files 450can be performed.

A description will now be given of a method of reproducing a virtualfile with reference to FIG. 161. It is now assumed that a command forcalling a file “X” is received at a step 481a. At a next step 481b, acheck is made as to whether only the contents of the directoryinformation suffice. If it is yes, the virtual directory entry in themagnetic file 422 is read out. At a step 481d, only the directorycontents such as the file name, the directory name, the file size, andthe making date and time are indicated on the display of the personalcomputer as shown by the, characters 496a on the screen 495 of FIG.164(a).

Here, screen indication is described. In FIG. 164(a), the indicatedcharacters 495b and 495c represent that a virtual file 450 is logicallypresent in the drive A, that is, the CD ROM 1a with the RAM. A 10-MBstill picture file and a 1-GB moving picture file can be recorded intothe virtual file 450. A 540-MB CD ROM file is also denoted by indicatedcharacters 496d. There are also indicated characters 496edenoting “fourfiles”. In this embodiment, the personal computer is provided with a 20GB hard disk. As shown in FIG. 160, the virtual disk setting capacityVMAX of the virtual disk with respect to one CD ROM 1a is recorded inthe sub disk ID column of the main machine ID number 474. One of thephysical file capacity of the sub disk ID number or the virtual disksetting capacity corresponds to the maximum recording capacity of thevirtual disk. The remaining recording capacity is equal to themaximum-recording capacity minus the currently-used capacity in thevirtual file. In the case shown by FIG. 164(a), a virtual file having atotal capacity of 10 GB is set, and a capacity of 1020 MB is used in thevirtual file. It is shown on the screen that a capacity of 8980 MBremains in the virtual file 450. The virtual file is denoted as theindicated characters 496g. The addition of the character “V” means avirtual file. Thus, the virtual file can be discriminated from otherfiles by referring to the character “V”.

As shown in FIG. 165 and FIG. 151, when the driver of the CD ROM 1a withthe RAM is separated into an A drive and a B drive, the ROM portion ofthe CD ROM is indicated as indicated characters 496h while the RAMportion of the CD ROM is indicated as indicated characters 496i and496j. Since the ROM and the RAM are separately indicated in this way,this design is advantageous in that easy handle by the operator isenabled. In the case of multiple-task processing, simultaneous readingand writing on the ROM portion and the RAM portion can be executed sothat a high processing speed can be attained.

Returning to FIG. 161, if it is no at the step 481b, an advance to astep 481e is done so that a check is made as to whether the ID number ofthe currently-used machine agrees with the main machine ID number 454 inthe virtual directory entry 452. If it is no, that is, if no physicalfile is present in the personal computer, a jump to a step 482a is done.If it is yes, that is, if a physical file 451 is present in the personalcomputer, an advance to a step 451f is done so that the drive number ofthe physical file is read out from the sub disk ID number 455. Then, acheck is made as to whether the drive is active. If it is no, anindication of commanding “turn on a drive corresponding to the drive IDnumber” on the display screen is performed at a step 481g. At a step481h, a check is made as to whether the drive has been activated. If itis no, stopping is done at a step 481i. If it is yes, an advance to astep 481j is done. At the step 481j, a check is made as to whether adisk corresponding to the sub disk ID number 455 is present. If it isno, an advance to a step 481k is done so that a check is done as towhether the disk is a replaceable recording medium such as an opticaldisk and a floppy disk by referring to the replaceable disk identifierin the sub disk ID number. If it is no, an indication “error” is givenon the display screen at a step 481n. Then, stopping is done. If it isyes, an indication “insert the disk” of the sub disk number ID 455 isgiven on the display screen at a step 481m. Then, a return to the step481j is done. If it is yes at the step 481j, an advance to a step 481qis done so that the corresponding file name 456 is searched for byreferring the directory region 465 of the disk corresponding the subdisk ID number. If it is decided to be absent at a step 481r, an errorindication is made at a step 481p. If it is decided to be present at thestep 481r, an advance to a step 481s is done and therefore collation ofthe information is executed to confirm that the physical file actuallycorresponds to the virtual file. Specifically, collation is made betweenthe data in the virtual directory entry 452 and the directory entry 467.In addition, collation is made between the disk ID number of the CD ROMand the main disk ID number 469 of the CD ROM side in the directoryentry 467. Furthermore, collation is made as to the change time and thefile size. No check is given of the characteristic. At a step 481t, acheck is made as to whether all the collated items are equal. If it isno, error indication is given at a step 481u. If it is yes, the readoutof the physical data of the corresponding file “X” in the directoryregion 465 starts to be executed at a step 481v. A FAT start clusternumber “YYY” is waited. At a step 481w, the cluster number continuous tothe FAT “YYY” is read out. A step 481x reads out necessary data amongthe data of the cluster number of the data region. At a next step 481y,the readout of the file “X” is completed. Therefore, the virtual file450 is provided with an arbitrary capacity within the capacity of thehard disk of the personal computer 408.

If the physical file corresponding to the virtual file is decided to beabsent from the hard disk of the present personal computer at the step481e, a jump to a step 482a is done so that the connection with thepersonal computer of the main ID number which contains the physical fileis started. In this case, the connecting routine 482 is in the networkOS. First, the LAN address of the main machine ID number is read outfrom the item of the main machine ID number in the virtual directoryentry. At a step 482b, the number of the connecting program is read out.The given network connecting program is executed, and thepreviously-mentioned LAN address is inputted to try the connection. Astep 482c checks the connection. If the connection fails, errorindication is made at a step 482d. If the connection succeeds, a commandof reading the file is transmitted to the sub personal computer 408a viathe network such as the LAN.

From a step 482g, OS work by the sub personal computer 408a is started.Data is read out from the physical file in response to a command ofreading the file “X” from the main personal computer. This work is sameas the previously-mentioned subroutine 483 for reading out the physicalfile data. Accordingly, the subroutine 483a uses the,previously-mentioned subroutine. At a step 482h, a check is made as towhether the readout of the file has been completed. If it is yes, anadvance to a step 482j is done so that the data of the file istransmitted to the main personal computer 408. Then, an advance to astep 482k is done. If it is no, an advance to a step 482i is done sothat an error message is, transmitted to the main personal computer.Then, an advance to the step 482k is done.

The step 482k is in the connecting routine 482 by the network OS in thepersonal computer 480 which is executed via the LAN. The step 482kreceives the data of the file or the error message from the sub personalcomputer 408a. At a step 482m, a check is made as to whether the errormessage is present. If it is yes, error indication is made at a step482p. If it is no, an advance to a step 482y is done to complete thework of reading the file.

With reference to FIG. 162, a description will now be given of a routine485a for rewriting the virtual file. If the user gives a command ofrewriting the data in the given file “X” at a step 485a as shown by theindicated characters 496 of FIG. 166(a), the virtual directory entry 452of the given file “X” is read out at a step 485b. At a step 485c, acheck is made as to whether a secret number is present in the file. Ifit is yes, indication “password?” on the display screen is made as theindicated characters 496p of FIG. 166(a) at a step 486d. The user inputs“123456” via the keyboard as denoted by the characters 496q. A check ismade as to whether this number agrees with the secret number. If it isno, error indication on the display screen is made at a step 485e. If itis yes, an advance to a step 485g is done so that a check is made as towhether the physical file 451 is present in the personal computer. Acheck is made as to whether the current machine ID number agrees withthe main machine ID number. If it is yes, an advance to a step 485 isdone. If it is no, an advance to a step 486a is done which is in aroutine 488 for the connection with another personal computer via thenetwork. The step 485h in a subroutine 487 for rewriting the physicalfile data extracts the drive name of the sub machine ID number from thevirtual directory entry 452, and a check is made as to whether the drivehaving the drive name is present in the personal computer. If it is no,characters 496r representing “turn on the drive power supply” areindicated on the display screen at a step 485i as shown in FIG. 166(b).At the step 485i, a check is made as to whether the drive is present. Ifit is no, an advance to a step 485j is done so that characters 456srepresenting “an error” is indicated on the display screen. If it, isyes, an advance to the step 485j is done. The step 485k checks whetherthe disk having the ID number same as the sub disk ID number 455 in thedriver is present. If it is no, a jump to a step 485m is done so thatthe replaceable recording medium characteristic is checked. If it isyes, indication “insert the replaceable medium disk xx” is made on thedisplay screen at a step 485n as shown in FIG. 166(d). Then, a return tothe step 485k is done. If it is no, a jump to the step 485j is done toexecute the indication of “error”.

If it is yes at the step 485k, the directory region 465 in the diskhaving the sub disk ID number is read out and then the correspondingfile name 456 is searched for and checked. If it is no, a jump to thestep 485j is done to execute the indication of “error”. If it is yes, anadvance to a step 485r is done so that a collation or check is made asto whether the physical file is the actual physical file in the virtualfile. Specifically, a check is made as to whether the contents of thevirtual directory entry 452 is equal to the data in the directory entry467 except the characteristic data. In addition, a check is made as towhether the disk ID number of the client-side CD ROM is equal to themain disk ID number 469 of the CD ROM in the server side disk entry.

At a step 485s, a check is done. If it is no, a jump to the step 485j isdone to execute the indication of “error”. If it is yes, an advance to astep 485t is done so that the system such as the OS temporarily erasesthe write inhibiting flag such as the characteristic data “01H” or “02H”in the directory entry of the file “X”. In this case, the recording isenabled. This file can not be seen from files other than the virtualfile of the CD ROM because of the presence of “invisible code”, and cannot be corrected also.

In this way, the virtual file can be seen from and corrected by only thecorresponding CD ROM so that the virtual file is protected. At a step485u, a check is made as to whether the disk having the physical filehas a free capacity. If it is no, the error indication is executed bythe step 485j. If it is yes, an advance to a step 485v is done so thatthe data in the corresponding file of the directory is read out and thestart cluster number is obtained. At a step 485w, the cluster numberwhich follows the start cluster number is obtained from the FAT region466. With respect to the data region 473, at a step 485x, the data inthe data region of the cluster number is rewritten. In the case wherethe amount of the new data is greater than the amount of the old data,the data is also recorded in the new cluster. In this way, the data isactually recorded into the physical file 451. At a step 485y, a check ismade as to whether the completion has been reached. If it is no, areturn to the step 485x is done. If it is yes, an advance to a step 485zis done so that the FAT and the directory of the physical file 451 arerewritten. At this time, the data “02H” corresponding to “invisible” isrecorded again into the characteristic of the directory entry 467. Thus,as shown in FIGS. 167(a) and 167(b), the substance of the physical fileis made invisible to the user. Accordingly, it is generally difficult toexecute rewriting other than rewriting of the virtual file 450 in the CDROM 1a by the OS. This design is advantageous in that the data can beprevented from being improperly rewritten. In the case where thepreviously-mentioned secret number is set for each virtual file, thedata is protected further.

An advance to a step 486n is done, so that the data in the directoryentry 467 except the characteristic data is transferred to the virtualdirectory entry 452 of the magnetic file. As a result, the contents ofthe two are the same in the items including the date and the time. Thus,during a later period, writing into the physical file 451 is permittedby the collating work upon rewriting. The operation work ends at a step486p.

If it is no at the step 485g, a jump to a step 486a is done so that theroutine 488 for the connection with the LAN is started. First, the LANaddress of the main machine ID number corresponding to the presence ofthe physical file is read out from the virtual directory entry 452. At astep 486b, a plurality of the numbers of programs are read out which aredesigned to provide the connection via the network such as the LAN fromthe LAN address “B” of the main personal computer 408 currently providedwith the CD ROM 1a to the sub personal computer 408a of the LAN address“A” of the main machine ID number as shown in FIG. 168. In addition, theLAN addresses are inputted, and the connecting programs are'successively executed. At a step 486c, a check is made as to theconnection. If the connection has been realized by one of the programs,an advance to a step 486ecorresponding to “yes” is done. If it is no, anadvance to a step 486d is done so that error indication is performed. Atthe step 486e, new data and a command of rewriting the physical file 451are, transmitted to the sub personal computer 408a.

Then, an advance to a step 486fis done. Here, the OS of the mainpersonal computer is replaced with the work by the input/output controlOS and the network OS of the sub personal computer 408a. The filerewriting command and the new data are received. At a next step, thesubroutine 487 for rewriting the data in the physical file is executed.At a step 486g, a check is made as to whether the file data rewritinghas succeeded. If it is yes, an advance to a step 486h is done so thatthe information of the completion of the rewriting and the newest datain the directory entry 467 of the physical file are transmitted to themain personal computer 408 via the network. Then, a jump to a step 486jis done which correspond to the work by-the network OS of the mainpersonal computer 408. If it is no at the step 486g, a jump to a step486i is done so that the error message is transmitted to the mainpersonal computer 408 via the network. Then, a jump to the step 486j isdone which corresponds to the work by the network OS of the mainpersonal computer 408.

At the step 486j which corresponds to the work by the network OS of themain personal computer 408, the error message or the data of thedirectory entry 467 of the physical file 451 is received from the subpersonal computer 408a. If the error message is decided to be absent bya step 486k, a step 486n rewrites the virtual directory entry 452 of thevirtual file 450 of the magnetic file of the CD ROM in response to thedata of the directory entry 467 which represents the items such as thedate. At a step 486p, the rewriting work ends. If the error message isdecided to be present at the step 486k, an advance to a step 486m isdone so that “error” is indicated on the display screen.

As shown in FIG. 168, the virtual file 450 having a capacity of, forexample, 10 GB can be logically realized in connection with the CD ROM2a having the RAM although the magnetic recording layer 3 of the diskhas only a capacity of 32 KB. The physical file may be defined in theHDD of the main personal computer or in the HDD of the sub personalcomputer 408a.

FIG. 220 shows an example where computers A and B are defined as themain machine 408 and the sub machine 408a respectively, and the hybridrecording medium 2 of this invention is inserted into the main machine408. When the optical ROM portion is defined as an F drive and themagnetic recording layer is defined as a G drive with respect to the CDROM, all the data in the F drive is actually present in the medium andcorresponds to an actual ROM file 468 or an actual ROM having a capacityof 540-600 MB. The magnetic recording layer being the G drive has acapacity of 32 KB, and an actual RAM file 469 has a capacity of 32 KB.As previously described, a virtual RAM file 470 is logically provided bythe OS or the device driver. The data in the virtual RAM file 470 isstored in a C drive being an HDD or an actual RAM file 471 in the HDD ofthe other personal computer 408a which can be accessed via a network472. Only when data A, data B, data C, data D, date E, and data F in thevirtual RAM file 470 are open or accessed, the OS reads out the datafrom the sub actual RAM file via a connection cable 473 in the actualRAM file 469 or the magnetic recording layer. Thus, the operation occursas if the actual data is stored in the virtual RAM file 470. Theconnection cable 473 stores a directory name secret number, the name ofa drive containing the actual RAM file 471, a connection protocol, anetwork address, and a TCP/IP address on a network of the computer 408ahaving the HDD storing the actual RAM file 471. The actual RAM file 471stores the actual data in the virtual RAM file 470. As long as thenetwork 472 remains effective via the connection cable 473, the OS canread out the data from the sub actual RAM file 471 which stores theactual data in the virtual RAM file 470. P As long as the networkremains connected and effective, it appears from the user that themagnetic file 422 stores the data A, B, C, D, E, and F of the files A,B, C, D, E, and F when the hybrid recording medium 2 of this inventionis inserted into any computer. In fact, the magnetic recording layerstores only the file directory entry information such as the filecharacteristic data such as the data of the making date and time, thecapacities and the names of the files A, B, C, D, E, and F, and thedirectory names. In the case of MS-DOS, the directory entry data has 32byes, and the hybrid recording medium of this invention can store about1000 files or directories since the magnetic recording layer therein hasa capacity of 32 KB. In this invention, the default value of the datacapacity, of each virtual file is set equal to that of a conventionalfloppy disk (1.44 MB), and good compatibility with the conventionalfloppy disk can be attained. As previously described, the default valuemay be set to 10 MB or 100 MB.

This design can be applied to an IC card or an optical disk having a ROMand a RAM. FIG. 220, FIG. 224, and FIG. 225 show an IC card having a ROMand a RAM and also being provided with a virtual RAM file. Generally, aROM in an IC card is cheaper than a RAM therein. According to an exampleof this invention, the capacity of the ROM in the IC card is set muchgreater than the capacity of the RAM therein to attain a low cost of theIC card. As previously described, when an apparatus for driving the ICcard is connected to a network, the RAM capacity of the IC card can bevirtually increased.

A description will now be given of a method of making a new virtual filewith reference to FIG. 163. It is assumed that, as shown in FIG. 169(a),at a step 491a, the user inputs the user ID number or a command ofsaving a new data file having a name “X”. The OS checks whether themagnetic file 422 has a free capacity. If it is no, stopping is executedat a step 491c. If it is yes, the sub disk ID number and the mainmachine ID number 474 of the default of the user ID number are read outat a step 491d. At a step 491e, screen indication is executed as shownin FIG. 169(a) to check whether the default is good. If it is no, theuser is forced to input a changed default value at a step 491f and thena check is executed again. If it is yes, an advance to a step 491g isdone so that a check is made as to whether the ID number of the mainmachine of the default which links with the virtual file is equal to theID number of the machine currently provided with the CD ROM. If it isno, an advance to a step 492a is done which lies in a network connectingsubroutine. If it is yes, an advance to a step 491h is done which liesin a new file registering subroutine 493. At the step 491h, a check ismade as to whether a disk having the ID number of the default ispresent. If it is no, a step 491i checks whether the disk is of thereplaceable type by referring to the data. If it is yes, “insert diskxx” is indicated as shown in FIG. 169(a). At a step 491k, a check ismade as to whether the disk has a physical capacity for providing aphysical file. If it is no, “error” is indicated at a step 491u. If itis yes, an advance to a next step 491m is done so that the data isstored into a free part of the data region 473 of the physical file fromthe cluster start number xx. At a step 491n, a check is made as towhether the data storing has been completed. If it is no, the errorindication is executed by the step 491u. If it is yes, the directoryregion 465 and the FAT region 466 of the physical file are rewritten inresponse to the record file. At a step 491q, the OS stores invisiblecharacteristic data such as “02H” into the characteristic 458 of thedirectory entry 467 of the physical file (see FIG. 160). Writeinhibiting data “01H” may be stored. The input control OS handles onlythe virtual file in a special way, and the recording and reproduction onthe file are performed while the file links with the virtual file.According to other operation sequences, neither the recording nor thereproduction can be performed. At a step 491r, a secret number and themain machine ID number are stored into the directory entry 467. At anext step 491s, unique information such as the file name and theregistration date and time which is equal in contents with the directoryentry 467 of the physical file 451 is stored into the virtual directoryentry 452 of the recording medium 2. Thereby, the collation with thephysical file 451 can be reliably executed when the virtual file isrewritten during a later period. In addition, a physical file 451 inanother personal computer on the network can be prevented from beingerroneously rewritten. The new file making routine ends at a step 491t.

If it is no at the step 491g in the connecting subroutine 488, anadvance to a step 492a is done so that the LAN address of the mainmachine is read out from the virtual directory entry 452, and theconnection with the main personal computer is executed via thee network.In addition, the physical file 451 for the virtual file 450 in the diskof the sub personal computer 408 is registered by using the new fileregistering subroutine 493, and the result is transmitted to the mainpersonal computer. The flow portion from the step 492a to a step 492j isequal to that in FIG. 162, and a description thereof will be omitted. Ata step 492i, the new registration is checked. Then, an advance to a step491s is done so that the data in the directory entry 467 of the physicalfile 451 is stored into the virtual directory entry 452 of the recordingmedium 2. At a step 491t, the new file registration is completed.

With reference to FIG. 271, a description will be given of displayoperation which occurs in the case of window display such as in a Mac OSor a Windows OS. The display operation is similar to that in a DOS OS ofFIGS. 164(a), 164(b), 164(c), and 164(d), FIG. 165, FIG. 166, and FIG.167 except for the following points.

Regarding FIG. 271, in the case where a CD-ROM 2 provided with a RAMaccording to this invention is inserted, a set of a CD-ROM icon 570 anda CD-ROM-RAM icon 571 is indicated. The composite icon differs in shapefrom an icon for a CD-ROM, and can be distinguished therefrom. Here, awindow 567a for indicating directories 568a, 568b, and 568c in the CDROM is opened, and the directories 568a, 568b, and 568c are indicated.When the CD-ROM-RAM icon 571 is subjected to double click, actuallyrecorded data is read out from a magnetic recording portion of theCD-ROM 2 which is a RAM portion. Data of directories 568d, 568e, and568f is transferred into in a window 567b from a master file for the RAMportion of the medium such as a magnetic recording layer before beingindicated on the display screen. In this invention, as previouslydescribed, a small-capacity master file for a virtual file is recordedon the magnetic record portion while a large-capacity slave file is madeinvisible and is recorded on an HDD. At that time, the window 567bindicates a substantial capacity 576 being 32 KB in the above-mentionedRAM portion, and also a virtual capacity 577 being “7.6 GB”representative of an actual file capacity physically assigned as a slavefile for the above-mentioned master file in the HDD 571.

In FIG. 271, the substantial data in the RAM portion is read out. Thus,only the data in the physical file which is described with reference toFIG. 160, that is, only the data recorded into the magnetic recordingportion of the CD-ROM 2, is read out, while the data in the virtual file450, that is, the physical file 451 in the HDD, is not read out at thisstage. Accordingly, regarding the CD-ROM 2 of this invention which has aRAM portion of 32 KB, the RAM capacity looks as being expanded to 7.6 GBfor the user. In this case, as shown in FIG. 271, the icon 570 for theROM portion of the CD-ROM 2 and the icon 571 for the RAM portion can beseparately subjected to click, and there is an advantage such thatopening can be independently done in connection with either the icon 570or the icon 571.

With reference to FIG. 272, when the icon 570 for the CD-ROM 2 issubjected to double click, composite windows 567a and 567b aresimultaneously opened which correspond to windows for the ROM portionand the RAM portion being integral with each other. The window 567a forthe ROM portion indicates the substantial capacity of the substantialfile actually present in the medium 2 which is 640 KB of the ROM portionof the CD-ROM 2. On the other hand, the window 567b for the RAM portionindicates the virtual capacity 577a of the slave file of the virtualfile not actually present in the medium 2 which is 7.6 GB, and also thesubstantial file 576a of the master file present in the medium 2 whichis 32 KB. In FIG. 272, the two windows are made integral, and the filesand the directories in the ROM and the RAM of the medium 2 are indicatedon a set of windows when the icon 570 is subjected to double click once.Thus, there is an advantage such that the number of times of keyinputting by the operator can be reduced. When a folder 568a is opened,a window 567c of the folder 568a is opened as shown by the arrow 51a sothat files 569a recorded in the CD-ROM medium are indicated.

On the other hand, a folder 568c indicated in the window 567b of the RAMportion can be displayed by reading out the substantial master file inthe medium 2. When the related icon is subjected to double click, awindow 576d of the folder A is opened as shown by the arrow 51b so thaticons for files 569b, 569c, and 569d are indicated. The file informationand the directory information which appear up to this process are storedin the RAM portion of the small capacity such as the magnetic recordingportion of the medium 2. Thus, it is unnecessary to read out a file 573and a folder 574, that is, a slave file, which is an actual physicalfile stored in a hard disk 572a with respect to the virtual file. Theoperator handles the apparatus as if the capacity of the RAM portion ofthe CD-ROM 2 is 7.6 GB or 520 MB. In this case, the file 573 and thefolder 574 of the substantial file for the virtual file are notindicated on the display as being an invisible file. Thus, in the casewhere a CD-ROM 2 is not inserted which is linked with a virtual file,the operator is prevented from doing a wrong process such as rewritingor erasing a substantial file. To this point, only the substantialmaster file in the medium 2 is opened.

With reference to FIG. 273, a description will be given of a process ofopening a program in the file 569 being the virtual file shown in FIG.272. When the user opens the file 569, it looks as if a large-capacityfile “file x” of 520 MB is actually present in the file 569 and is openas shown by the dot line arrow 51c. In fact, the actual slave file ispresent in the HDD 571, and the invisible file 573b in the invisiblefolder 574c in the invisible folder 574a which is invisible on thedisplay screen is opened by the previously-mentioned OS as shown by thearrow 51d. A large-capacity file for DTP is opened together with theprogram stored in the ROM portion. For example, as an indication 575,operation is done as if the capacity of the RAM portion is 520 MB.

In the case where “visualize the slave file” is selected from a pulldown menu, an indication is given of a window 567f for visualizing theslave file. When a correct password is inputted into a password inputportion 578a of the window 567f, an invisible file 573b is visualizedwhich corresponds to the password as shown by the arrow 51g. In the casewhere “erase virtual file” is selected from the pull down menu, anindication is given of a file erasing window 567f. When the file name isinputted into a file name input portion 579 of the window 567f and apassword corresponding to the file is inputted into the password inputportion 578b, the physical file of the invisible file 573 is erased fromthe HDD 571. In this way, it is possible to erase an unnecessary fileamong the slave files of virtual master files in the HDD 571. Since theslave files in the linked HDD can be arranged, the HDD can beefficiently used. In addition, since a slave file is protected by apassword, the slave file is prevented from being erased by otheroperators. In this way, slave files are protected which correspond tomaster files in the RAM portion of the CD-ROM.

Substantial slave files for virtual master files can be set in an HDD571a of another computer B via a network shown in FIG. 273. Also in thiscase, indication and erasion can be inhibited by using passwords.

With reference to FIG. 274, a description will be given of a way ofindicating a virtual file in a window according to a Mac OS or a WindowsOS. When a CD-ROM is inserted at a step 566a, an icon for a CD-ROM/RAM 2is indicated at a step 566b. In the case where a folder or a directorybeing first information is opened at a step 566c, a window 567a isopened which shows the directory of the first information in the ROMportion of the CD-ROM/RAM at a step 566d as shown in FIG. 271. In thecase where the directory of second information is opened at a step 566e,the directory 568d of the RAM portion of the CD-ROM/RAM is opened at astep 566f. At a step 566g, an indication is given of a virtual capacity576 of a virtual file “file x” recorded in a master file of the ROMportion, a substantial capacity 577, a home machine name of a personalcomputer containing a substantial slave file, a home address, a drivename, and a directory name in a file property indication window 567. Atthis time, it is good to open only the master file of the virtual file.It is unnecessary to open a slave file in HDD's 571 and 571a in FIG.273. In the case where a slave file in a virtual file being secondinformation is opened at a step 566k, advance to a step 566i is done.When a home machine ID number and an ID number of the currently-operatedcomputer A are equal to each other, advance to a step 566j is done. Inthis case, since the home HDD is directly connected to the computer A,connection with a network is unnecessary. When the numbers are not equalat the step 566i, advance to a step 566p is done. Here, a home machinestoring a slave file is a computer B other than the computer A connectedwith the CD-ROM as shown in FIG. 273. Thus, it is necessary to executeconnection with the network. Accordingly, at the step 566p, a check ismade as to whether or not connection with the network is present. If itis no, advance to a step 566m is done. At the step 566m, “network is notconnected” is indicated as shown in a network condition indicatingwindow 507h in the display portion 16 of FIG. 273. Then, return to thestep 566p is done. If it is yes, advance to a step 566m is done andconnection with the home machine via the network is executed. Then,advance to a step 566j is done. At the step 566j, since the CD-ROMmedium 2 is linked with the substantial slave file of the virtual file,an invisible file 573 is opened which is of the physically-present slavefile of the home directory of the HDD 571 being a home drive of the homemachine corresponding to the virtual file of the CD-ROM. At a step 566k,as shown in FIG. 273, “file x” having a capacity of 520 MB is opened. Asa result, a program such as a DTP program is started which is stored inthe CD-ROM.

The OS of this invention executes the previously-indicated processes.Thus, in the case where a medium being a CD-ROM 2 is used which has alarge-capacity ROM portion storing a software and a small-capacity RAMportion, the capacity of the RAM portion can be virtually expanded to alarge capacity of several GB. In this case, a physical file being aslave file is stored in a memory actually present in the home HDD 571 ofthe home machine connected via the network or the machine provided withthe CD-ROM/RAM. It is good to record a small amount of information intothe RAM portion of the medium. The small, amount of informationcorresponds to several tens of bytes, and contains information forconnection via the network such as an address of the home machine withthe home HDD and also information of the date, the capacity, and thedirectory of the actually-present substantial file. Thus, it is goodthat the physical capacity of the RAM portion of the CD-ROM/RAM issmall. According to window indication as in FIGS. 271, 272, and 273, anactual file 573 for a virtual file is an invisible file which is notindicated in a window at all. Thus, the icon 571 for the RAM portion ofthe CD-ROM 2 can be seen by the operator. Accordingly, for the operator,the apparatus looks as if a file of several hundreds of MB or several GBis stored in the icon 571 for the RAM portion. There is an advantagesuch that the RAM of 32 KB can be handled as a large-capacity RAM ofseveral GB. Since a physical file being a slave is protected by apassword and is invisible, the physical file is prevented from beingerased by other operators. In the case where a physical filecorresponding to a virtual file is required to be indicated or erasedwithout an original CD-ROM/RAM, the visualizing window 567f is used anda password is inputted so that the invisible file is made into a visiblefile.

According to this invention, when a virtual file is required to be newlyset, a window 567 is indicated. A home machine name, a file name and apassword are inputted into the window, and thereby the virtual file canbe set. When a physical file is required to be erased, indication isdone as in a window 567g. A file name and a password are inputted intothe window, and thereby the physical file is erased without a CD-ROM/RAM2 being a master. Even if a master CD-ROM/RAM 2 is lost, a physical fileor a slave file for a virtual file can be erased. Accordingly, thisinvention can arrange slave files, that is, substantial files 573, ofvirtual files in the HDD 571.

As previously described, a CD-ROM/RAM is used in combination with an OSsuch as a Windows OS or a Mac OS which contains a CD-ROM driversoftware. In this case, by using a virtual file for a CD-ROM/RAMaccording to this invention, the capacity of the ROM portion of theCD-ROM can be virtually expanded. When both a low-cost CD-ROM/RAM medium2 of this invention and a virtual file of this invention are used, thereis provided an advantage comparable to or greater than the advantage ofa prior art expensive optical disk of the partial ROM type.

It should be noted that a virtual file may be set in a RAM portion of amedium with a ROM such as an optical disk of the partial ROM type or anIC card with a ROM.

The recording medium 2 will now be described. In the case where thedirectory information is recorded into the magnetic recording layer, thevirtual file is damaged if the information is damaged. Thus, in the casewhere this design is applied to a CD ROM, equal virtual directoryentries are recorded into two or three physically separated places asshown in FIG. 171. To protect the directory information from acircumferential scratch on the disk, the recording into separate tracks67x, 67y, and 67z is executed To protect the directory information froma radial scratch on the disk, the directory entries 452x, 452y, and 452zare located at different positions of angles θx, θy, and θzrespectively.

According to this invention, the system provides a physical file andlogically defines a large-capacity virtual file in the RAM portion of anoptical disk 2 by using a capacity of an HDD as previously described.Thus, the optical disk having a small-capacity RAM can be handled as aROM disk with a large-capacity RAM. Even in the case where the mainpersonal computer 408 into which the optical disk 2 is inserted lacksthe server side physical file 451 corresponding to the virtual file 450,the data is recorded and reproduced by automatically accessing thephysical file 451a of the sub personal computer 408a via the network asshown in FIG. 168.

This design is advantageous in that the physical file corresponding tothe virtual file can be accessed when the optical recording medium 2 ofthis invention is inserted into any personal computer. This design canbe realized by an application program.

As previously described, the recording medium 2 has an optical recordingsurface. The back side of the recording medium 2 is provided with themagnetic recording layer 3. In the recording and reproducing apparatuswhich executes the RAM type recording, and reproduction such as themagneto-optical recording and reproduction, the magnetic head is used incommon for the two purposes. Thus, without substantially increasing thenumber of parts and the cost, it is possible to magnetically recordinformation of independent channels provided on the recording medium. Inthis case, the slider tracking mechanism for the magnetic head isoriginally provided so that an increase in the cost of the recording andreproducing apparatus hardly occurs. Thus, there is an advantage suchthat the magnetic recording and reproducing function which isindependent of the optical recording can be added at essentially thesame cost.

The recording medium containing the recorded information is applied to amusic CD, an HD, a game CD ROM, and an MD ROM, and the back side thereofis provided with the magnetic recording track. This recording medium issubjected to the reproducing process by the ROM type recording andreproducing apparatus of FIG. 17. Thereby, there is provided anadvantage such that the conditions which have been previously used canbe retrieved upon the reproduction. As described with respect to thefirst embodiment, in the case where the recording is limited to only onetrack of the TOC area, information of several hundreds of bits can berecorded when the gap width is set to 200 μm. This capacity meets therequirements for use of a game IC ROM with a nonvolatile memory. In thecase of limitation to the TOC, a device for accessing the magnetic trackcan be omitted so that the structure of the system can be simple.

In the recording and reproducing apparatus which is exclusive for thereproduction regarding the optical recorded information, it is necessaryto provide the magnetic head and others at the opposite side of theoptical head with respect to the recording medium The related parts canbe common to the magnetic field modulating head for the magneto-opticalrecording, so that the cost of the apparatus can be lowered by massproduction. The parts are originally very cheaper than optical recordingparts and magnetic recording parts for a low density, and thus anincrease in the cost is small. Since the optical head is mechanicallylinked with the magnetic head located at the opposite side thereof, itis unnecessary to add a related tracking mechanism. Thus, in thisregard, an increase in the cost is small.

The time information or the address information is recorded on theoptical recording layer at the surface of the recording medium of theRAM type or the ROM type. The tracking with respect to the optical headis executed in response to the time information or the addressinformation. Thereby, the tracking control is done so that the magnetichead can move to an arbitrary position on the disk. Thus, there is anadvantage such that it is unnecessary to use expensive parts such as alinear sensor and a linear actuator.

The protective layer on the back side of a conventional magneto-opticrecording medium of the magnetic field modulation type is formed frombinder and lubricant by spin coat. In this invention, it is sufficientthat the magnetic material is added to the combination of the binder andthe lubricant, and the spin coat is executed at the same step. Thus, thenumber of manufacture steps does not increase. A related increase in thecost is in a negligible order relative to the entire cost. Therefore,the new value being the magnetic recording function is added withoutsignificantly increasing the cost.

As previously described, in this invention, the magnetic channel can beadded without significantly increasing the cost. In addition, the RAMfunction can be added to a conventional disk of the ROM type and aplayer exclusively for a ROM.

The high Hc magnetic sheet of this invention is attached to the labelportion of a video tape cassette or an audio tape cassette. Upon theloading of the cassette, data is read out from the magnetic sheet by themagnetic head 8. The readout data is stored into the IC memory in themicrocomputer. In the case where the data on the magnetic sheet isrequired to be updated only the contents of the IC memory are updatedduring the insertion of the cassette. When the cassette is ejected fromthe apparatus, only the updated data in the IC memory is recorded intothe magnetic recording layer by the magnetic head fixed near thecassette insertion opening. Thereby, the index information such as theTOC and the address of the cassette tape can be recorded on the cassetteseparately from the tape. This design is advantageous in that the searchfor the information in the cassette tape can be quickly executed.

This invention can be applied to a video game machine connected to adisplay 44a and a key pad 450A as shown in FIG. 180. The reproductioncan not be performed if an illegal copy identifying signal is notrecorded on the magnetic recording layer 3. This design is advantageousin that a CD made by illegal copy can be excluded. Data such asenvironment setting data, the name of the user, the point, and theresult at a mid part of the game is recorded into the magnetic recordinglayer 3. Thus, the game can be restarted from the conditions which occurat the end of the preceding play of the game. As shown in FIG. 180, themagnetic recording layer 3 is provided at the print surface side of theCD. As previously described, the magnetic recording layer 3 may beprovided at the transparent substrate side. This design enables a smallsize of the cassette.

DESCRIPTION OF THE TWENTY-THIRD PREFERRED EMBODIMENT

FIG. 181 shows a recording and reproducing apparatus according to atwenty-third embodiment of this invention. As shown in FIGS. 182(a) and182(b) and FIGS. 183(a)-183(e), a magnetic head is moved onto a CD onlywhen an upper lid 389 is closed. In FIG. 182(a), the upper lid 389 is inan open state. When the upper lid assumes the open state, the magnetichead 8 is retracted to a position below a magnetic head protectiveportion 501 extending outside the CD 2. The retraction of the magnetichead permits the CD to be inserted into the apparatus.

The CD 2 is inserted into the apparatus, and the upper lid is moved to aclosed state. During the movement of the upper lid to the closed state,the magnetic head 8 and its suspension move in a direction 51 to a placeabove the CD 2 according to the movement of the upper lid.

The operation sequence will now be described with reference to FIGS.183(a), 183(b), 183(c), 183(d), and 183(e). In FIG. 183(a), when theupper lid 389 is closed in a direction 51a, lid rotation shafts 393 and393a rotate so that a head retracting device 502 moves in a direction51b and the magnetic head 8 connected thereto moves in a direction 51c.In this way, as shown in FIG. 183(b), the magnetic head 8, a slider 41,and a suspension 41a move to a place above the recording medium 2 suchas the CD.

Upward and downward movement of the magnetic head 8 will now bedescribed with reference to FIGS. 183(c), 183(d), and 183(e). As shownin FIG. 183(c), an optical head 6 executes the reproduction on aninnermost track 65a of the TOC and others. As shown in FIGS. 184(a),184(b), and 184(c), a medium identifier 504 is read out, and a check ismade as to whether the medium has a magnetic track 67 by referring tothe medium identifier 504. If the medium actually has a magnetic track67, the optical head 6 is moved to a place inward of the innermost trackas shown in FIG. 183(d). A head elevator 505 is forced by a headelevating link 503, bringing the magnetic head 8 into contact with anoutermost magnetic track 67a and enabling the recording or reproductionof a magnetic record signal via the magnetic head 8.

As shown in FIG. 185(a), a servo signal region 505 is provided. Duringthe manufacture of a recording medium, a high Hc portion is appliedthereto as shown in FIG. 185(b). As shown in FIG. 185(c), the recordingmedium is formatted in a factory or others. A servo signal selectorinformation, and a medium identification number are recorded on a syncsignal region 507 medium by medium. This recording is executed by usinga magnetic head capable of recording information into a magnetic regionhaving an Hc of 2750-4000 Oe. Next, as shown in FIG. 185(d), a low Hcmagnetic portion 402 is applied. The low Hc magnetic portion 402 is madeof material having an Hc of 1600-1750 Oe. As shown in FIG. 185(e), aprotective layer 50 is applied thereon.

The magnetic portion 402 and the protective layer 50 make it moredifficult to rewrite the information in the high Hc magnetic portion.Thus, the medium identification number 506 recorded in the sync signalregion 507 can be more reliably prevented from being rewritten. Thisdesign is advantageous in that the previously-mentioned illegal copyguard function is hardly removed.

The servo signal 505 and the address signal can not be erased by aconventional recording and reproducing apparatus. Thus, after theshipment of the medium from the factory, the data in the sync signalregion can be maintained and protected so that stable data recording canbe realized in response to the data in the sync signal region.

Rotation servo will be further described with reference to FIG. 183(d).In the presence of an optical recording portion at an innermost part ofthe CD 2, the rotational speed of a motor is made constant by CLV motorrotation control in response to the sync signal in the optical track. Inthis case, the magnetic recording and reproduction are enabled.

In the absence of an optical recording portion from an innermost part ofthe CD 2, the magnetic head 8 reproduces the servo signal 505 from thesync signal region 507 of FIG. 185(a). A rotation servo signal is thusreproduced by a rotation servo signal reproducing section 30c of FIG.181. The rotation servo signal is transmitted to a motor drive circuit26 so that the motor is controlled at a constant rotational speed.Therefore, data can be recorded and reproduced into and from desiredsectors in data recording regions 508 and 508a of the magnetic track 67aof FIGS. 185(a), 185(b), 185(c), 185(d), and 185(e).

After the recording or reproduction has been completed, the optical head6 moves toward a disk outer portion as shown in FIG. 183(e). Thereby,the head elevating link 503 returns to the original position, and themagnetic head 8 moves in a direction 51e and separates from the magnetictrack 67a. The separation of the magnetic head 8 from the magnetic track67a prevents a wear problem. In this way, the magnetic head 8 can bemoved upward and downward by a traverse motor 23. This design isadvantageous in that it is unnecessary to provide another head elevatingactuator.

As shown in FIGS. 186(c), 186(d), 186(e), the optical head 6 is forcedto an outermost portion of the disk by the traverse motor 23, and thehead elevating link 503 is moved in the direction 51a. The magnetic head8 is lowered along the direction 51b into contact with the magnetictrack 67a so that the recording and reproduction of the magnetic signalare enabled. In the case where magnetic noise from the optical head 6causes a problem, the operation of an optical head actuator 18 issuspended. When the operation is suspended or when the reproduction of asignal from the optical track can not be executed, a drive current tothe optical head is cut off. In addition, the servo signal 505 in themagnetic track of FIG. 185(a) is reproduced via the rotation servosignal reproducing portion 30c of FIG. 181, and rotation servo controlis executed in response to the reproduced servo signal. Thereby, it ispossible to temporary separate the optical reproduction and the magneticreproduction. Since the noise from the optical head is thus preventedfrom interfering with the magnetic reproduction, an error rate can besmall in the magnetic reproduction.

The arrangement of this embodiment can be applied to the plural magnetictrack type or the one magnetic track type. In the case of a one tracksystem, access to the head is unnecessary so that the apparatus can besimple in structure. In the case of one track at a disk outermost part,the capacity is large. As shown in FIGS. 187(a), 187(b), 187(c), 187(d),and 187(e), the recording medium has sectors provided with the syncsignal region 507, into which the magnetic servo signal 505 is stored ina factory or others. Upon the magnetic reproduction, the servo controlresponsive to the optical signal is replaced by the servo controlresponsive to the magnetic signal so that the drive current to theoptical head 6 can be cut off. Thus, the noise from the optical head canbe prevented from occurring.

A method of the rotation servo control responsive to the optical servosignal will now be described with reference to FIGS. 188(a)-188(f). FIG.188(a) show conditions which occur at t=0. The optical head 6 is in aposition corresponding to an outer track or a TOC track 65a. In FIG.188(b), at t=t1, the optical head 6 reads out information from the TOCtrack 65a. A medium identifier 504 is found out from the subcode of theTOC, the subcode portion of an audio track, or the first track of a CDROM as shown in FIG. 184(c), FIG. 184(b), and FIG. 184(a). At this time,since the head elevating link 503 moves from a position A to a positionB according to the movement of the optical head 6, a switch 511 of amechanical delay device 509 is moved to an on position. Until a delaytime tD elapses, the head elevating link 503a remains inactive. In FIG.184(c), at t=t2, the reproduction of the TOC data is completed. In thecase where the delay time tD is set as tD>t2, the magnetic head 8 is notmoved downward. In the absence of a medium identifier, that is, in anoff state, tD>t3. In FIG. 188(d), at t=t3, the optical head 6 moves inthe direction 51d, and the head elevating link 503 suspends pressing theswitch 511 so that the head is not moved downward.

In the presence of a medium identifier, there is always a magnetic track67a. In an on state, at t=t4 (t4>tD), the switch 511 remains pressed forthe delay time tD or longer as shown in FIG. 188(e). Therefore, theoutput of the mechanical delay device 509 becomes effective, and thehead elevating link 503a moves downward a support portion including thesuspension of the magnetic head 8 in the direction 51e. As a result, themagnetic head 8 contacts the magnetic track 67a. At this time, since theoptical head 6 executes the reproduction on the optical track 65a of theTOC or others, the optical servo signal is reproduced. The motor 17 isrotated at a constant rotational speed by the CLV control responsive tothe optical servo signal. Accordingly, the magnetic signal is reproducedin synchronism with the sync signal of the optical reproduced signal.Since the rotation servo control can be executed simultaneously inresponse to the magnetic reproduction and the optical reproduced signal,it is unnecessary to provide another mechanism for rotation servocontrol. Thus, this design is advantageous in that the medium and theapparatus can be simple in structure. In this case, the rotation servosignal reproducing portion 30c may be omitted from the arrangement ofFIG. 181.

When the reproduction or recording of the magnetic signal has beencompleted, the system controller 10 of FIG. 181 transmits a given signalto the traverse moving circuit 24a so that the optical head 6 is movedin a direction 51f and the switch 511 of the mechanical delay device 509is released. At t=t5 after a delay time tDS shorter than the delay timetD elapses, the head elevating link 503a moves upward along a direction51g as shown in FIG. 188(f) so that the magnetic head 8 is elevated outof contact with the magnetic track 67a. In this way, a simplerarrangement enables the upward and downward movement of the magnetichead, and the optical reproduction and the magnetic reproduction can besimultaneously executed.

As shown in FIGS. 185(a), 185(b), 185(c), 185(d), and 185(e), aplurality of magnetic tracks 67 may be used. In this case, as shown inFIG. 189(a), the track width TWH of the magnetic track 8 is set greaterthan the width TW of the magnetic track 67a by a quantity correspondingto an eccentricity amount (an off-center amount). This design isadvantageous in that a single head can be used in common for recordingand reproduction. When the widths are set as TWH>>TW, the recording intoall the magnetic track 67a can be executed so that thepreviously-recorded portion will not be left at all. In the case wheremagnetic layers corresponding to a plurality of tracks are separatelyprovided, a single head can be used as both a recording head and areproducing head.

In the case of the multiple track system, setting of the track pitch Tpis important. The CD standards allow an error Δr of ±0.2 mm between theposition of an optical track 65 and the center of the CD circle in theradial direction. Under ideal conditions, as shown in FIG. 189(a), amagnetic track 67a is located at the back side of a given optical track65a, and access to the magnetic track by referring to the opticaladdress can be accurately executed. Under actual bad conditions, asshown in FIG. 189(b), the optical track 65a and the magnetic track 67aare offset by +Δr. Under opposite actual bad conditions, as shown inFIG. 189(c), the optical track 65a and the magnetic track 67a are offsetby −Δr. To prevent the magnetic head 8 from accessing a magnetic track67b neighboring the desired magnetic track, it is necessary to satisfythe following conditions.r−Δr−TWH/2>r+Δr+TWH/2−TpAccordingly, the following relation is obtained.Tp>2Δr+TWHIn the case of a CD, Δr=0.2 mm so that the track pitch Tp is determinedby the following relation.Tp>0.4 mmThus, it is necessary to set the track pitch Tp to 0.4 mm or greater.

As shown in FIG. 187(a) and FIG. 189(a), the separate magnetic recordinglayers are provided, and the magnetic servo signal is recorded thereintoby a single magnetic head. In this case, as shown in FIG. 190, thestructure of the arrangement can be simple.

As shown in FIGS. 183(c), 183(d), and 183(e), the magnetic head 8 ismoved upward and downward by using the traverse motor 23. This method ofmoving the magnetic head 8 can be applied to an arrangement where anoptical head 6 and a magnetic head 8 are located on a common side of arecording medium as shown in FIGS. 191(a), 191(b), 191(c), 191(d), and191(e). In the case where an identifier is detected under condition of aTOC track 67a in FIG. 191(c), the optical head 6 moves to a state ofFIG. 191(d) along a direction 51a. Therefore, a head elevating link 503moves in the same direction, raising the magnetic head along a direction51b into contact with the magnetic track 67a provided on an outer areaof the optical recording surface side of the medium. Then, the magneticrecording, or reproduction via the magnetic head 8 is performed. At thistime, the optical head reproduces an optical servo signal from anoptical track provided on an inner area of the medium, and rotationservo control for rotation at a constant speed is executed in responseto the reproduced optical servo signal. The rotation servo control maybe performed in response to the magnetic servo signal reproduced fromthe magnetic track 67a. After the magnetic recording or reproduction hasbeen completed, the optical head 6 moves outward as shown in FIG. 191(e)and the magnetic head 8 moves downward out of contact with the medium.

FIGS. 192(c) and 192(d) show another design in which an optical head 6moves along a direction 51a to a region outside an outer edge of arecording medium, and thereby a magnetic head 8 is raised along adirection 51b into contact with a magnetic track 67a. Operationaccording to this design is approximately similar to the operation ofthe design of FIGS. 186(a), 186(b), 186(c), 186(d), and 186(e).

As previously described, the magnetic recording track 67a is provided onan outer area of the optical recording surface side of the recordingmedium. Even in the case where the magnetic head 8 and the optical head6 are located on the same side of the recording medium, the magnetichead 8 is moved upward and downward by the traverse motor 23 so that thenumber of parts can be reduced.

According to a CD player of FIG. 193(a), when an upper lid 389 is openbut a CD is not inserted into the player, a magnetic head 8 and asuspension 41a are exposed. The magnetic head 8 and the suspension 41atend to be damaged by a touch thereto.

To prevent such a problem, a magnetic head shutter 512 covers themagnetic head 8 when the upper lid 389 is open. As a CD 2 is insertedinto the player and the upper lid 389 is closed, the magnetic headshutter 512 moves in a direction 51a to uncover the magnetic head 8.This process will be further described. With reference to FIG. 191(a),as the upper lid 389 is closed in a direction 51, a lid rotation shaftrotates in a direction 51d and the magnetic head shutter 512 moves in adirection 51e. Therefore, as shown in FIG. 191(b), a magnetic headwindow 513 is unblocked so that the magnetic head 8 is permitted to moveupward and downward. In this regard, the arrangement of FIGS. 192(a) and192(b) is similar. This design is advantageous in that the magnetic head8 and the suspension 41a can be protected by the magnetic head shutter512.

There is no problem in an arrangement where a magnetic head 8 and atraverse of an optical head 6 are adequately separate as shown in FIGS.193(a) and 193(b). On the other hand, in the case where a magnetic head8 is located in a range of movement of a traverse, the magnetic head 8is provided with a spring 514 as shown in FIG. 194(e). In this case,only when an optical head 6 executes the reproduction on an outermostoptical track 65a, the magnetic head 8 is forced in a direction 51a bythe optical head 6 so that the magnetic head 8 is retracted outward.This design is advantageous in that an adequate access range of theoptical head 6 can be maintained. This design is effective in the caseof a recording medium such as a CD having a magnetic recording track 67awhich is not provided on the optical recording surface side thereof

FIGS. 222(a)-222(f) show arrangements in which a magnetic track 67 isprovided on a ROM disk being an MD (mini disk) in a cartridge 42. Asshown in FIG. 222(a), one side of the cartridge 42 for the MD ROM diskhas a small radially-extending shutter window 302. Thus, a magnetic head8 and an optical head 6 are located on a common straight line 514c.Therefore, A tracking range of the optical head 6 overlaps the positionof the magnetic head 8. The presence of the magnetic head 8 makes itdifficult for the optical head 6 to access an outermost optical track65a.

According to this invention, as shown in FIG. 222(e), a magnetic head 8is designed to be movable in a radial direction, and the magnetic head 8is pressed against a stopper 514c by a spring 514 and is normally heldin a given position. When an optical head 6 access an outermost opticaltrack 65a as shown in FIG. 222(f), the magnetic head 8 (8a) istemporarily retracted or moved out of a range of movement of the opticalhead 6. In this way, the optical head 6 is permitted to access theoutermost optical track 65a even if the magnetic head 8 is provided at ashutter window 302. As the optical head 6 moves back to an inner region,the magnetic head 8 is returned to the given position by the spring 514and the stopper 514c. The magnetic track 67 has only one track providedon an outermost area of the optical reading side of the recordingmedium. The magnetic track 67 has a given thickness or height h. Thethickness of the mangetic track 67 prevents contact with the opticalrecording portion which might adversely affect the optical recordingportion. The position of the magnetic track 67 relative to the recordingmedium enables a large recording capacity, thereof. Positionalinterference between the magnetic head and the optical head can beremoved by the previously-mentioned arrangement for retracting themagnetic head. This design is advantageous in that a ROM disk having amagnetic recording layer and a recording and reproducing apparatustherefor can be realized while the ROM disk can be compatible with aconventional MD disk.

As shown in FIG. 222(a), a ROM medium having a magnetic recording layerhas an identification hole 313a for the magnetic recording layer. Acartridge of a recording medium without any magnetic recording layerdoes not have any identification hole 313a. When such a cartridge isinserted into an apparatus as shown in FIG. 222(c), a magnetic headmotion inhibiting device 514b is pressed and activated to that amagnetic head 8 is forced into a state where upward and downwardmovement of the magnetic head 8 are inhibited. This design isadvantageous in that the recording medium 2 can be prevented from beingdamaged by erroneous movement of the magnetic head 8 thereto. Themagnetic head 8 remains movable in the direction of an optical headmoving region, and an optical head 6 is permitted to access an outermostoptical track 65a.

When the recording medium 2 with the magnetic recording layer isinserted into the apparatus as shown in FIG. 222(d), the identificationhole 313a for the magnetic recording layer prevents downward movement ofthe magnetic head motion inhibiting device 514b so that upward anddownward movement of the magnetic head 8 remain permitted. The magnetichead motion inhibiting device 514b can be formed by simple mechanicalparts.

When the optical head 6 is in a position other than an innermost region,the magnetic head 8 is in an off state as shown in FIG. 222(c). Withreference to FIG. 222(e), as the optical head 6 moves to the innermostregion, a head elevation connecting device 514a moves in a direction 51band the magnetic head 8 is raised in a direction 51c into contact with amagnetic track 67a. In this way, the magnetic recording or reproductionis enabled. With reference to FIG. 222(c), as the optical head 6 returnsfrom the outermost region to a normal position, the magnetic head 8 islowered out of contact with the magnetic track 67a. In the case of a CDor an MD, when the disk is inserted into the apparatus, TOC informationis always read out for several seconds. In this invention, during thisperiod, the magnetic head 8 contacts the magnetic track 67a andreproduces the magnetic data therefrom. Since the optical reproductionon the TOC area is simultaneously executed, the rotation servo controlis enabled. In addition a write clock signal for the magnetic recordingcan be derived by frequency-dividing the optical sync clock signal.Since the upward and downward movement of the magnetic head are enabledby the traverse motor for the optical head, the structure of theapparatus is simple.

In the case where the data on the magnetic track 67a is required to berewritten upon the end of the disk reproduction process, the opticalhead 6 is moved again to the innermost area so that the magnetic head 8contacts the magnetic track 67a. Magnetic track data is written into themagnetic track 67a from a cache memory 34 of FIG. 1 via the magnetichead 8. After the writing process is completed, the optical head movesback to the original position so that the magnetic head 8 is moved outcontact with the magnetic track 67a.

In some of cases where an optical head 6 and a magnetic head 8 arelocated on opposite sides of a recording medium respectively, a magnetgenerates a strong magnetic field depending on the designing of theoptical head 6. FIG. 195 shows experimentally measured data of amagnetic filed on an optical recording portion of a CD which is causedby a CD ROM optical pickup made by “SANYO”. The magnetic field is equalto 400 gauss in the absence of a magnetic head, and is equal to 800gauss in the presence of a magnetic head 8 opposing the optical head.Thus, in this case, when the magnetic coercive force Hc of the magneticrecording portion of the recording medium is low, magnetically recordeddata tends to be erased. According to this invention, such a problem issolved by setting the magnetic coercive force Hc to 1500 Oe or more. Inaddition, according to this invention, the magnetic head 8 is preventedfrom opposing the optical head when the optical head is used.Specifically, as shown in FIG. 196(c), a magnetic head retracting link515 is moved while being linked with a traverse. When the optical head 6accesses an outer optical track 65a, the magnetic head 8 is forced bythe retracting link 515 to a outward of the recording medium 2. As aresult, the concentration of magnetic fluxes by the magnetic head 8 isprevented so that the recorded magnetic data can be prevented from beingdamaged.

As shown in FIG. 116, the optical head 6 also causes ac magnetic noisein addition to the previously-mentioned dc magnetic field noise. Asshown in FIG. 197, the magnetic head 8 is separated by a given distanceLH or more from the optical head 6 containing an optical head actuator.This design is advantageous in that dc and ac noises from the opticalhead 6 are prevented from entering the magnetic head 8. It is understoodfrom FIG. 116 that the noise level can be reduced by 15 dB when thegiven distance LH is equal to 10 mm. Thus, it is preferable that the twoheads are separated by 10 mm or more.

According to an arrangement using a multiple track head 8 for providinga magnetic track 67a divided into three as shown in FIG. 198(a), anincreased capacity of magnetic recording is attained. In the case wherea magnetic head 8 corresponds to three azimuth heads 8a, 8b, and 8c ofdifferent azimuth angles, the track density can be increased by threetimes. In the case of a non-azimuth head, a required track pitch Tp isequal to 0.4 mm in track width. In the case of an azimuth head of thistype, the required track pitch Tp is equal to 0.13 mm in track pitch. Inthe case of azimuth heads 8a and 8b of different azimuth angles as shownin FIGS. 198(c) and 198(d), a double recording capacity is attained.

A description will now be given of a method of recording a mediumidentifier into a TOC area. Optical tracks 65a, 65b, 65c and 65d arewove and wobbled as shown in FIG. 199(b), and thereby an additionalsignal (a wobbling signal) is recorded into the TOC area of FIG. 199(a).As shown in FIG. 200, an optical reproducing section is provided with awobbling signal demodulator 38c which functions to reproduce thewobbling signal. According to this design, information of a mediumidentifier and others can be recorded into the TOC area. This design isadvantageous in that the medium can be identified only by executing thereproduction on the TOC area, and that tune names and title names can berecorded into the TOC area.

In the case of a CD player of the tray type such as shown in FIGS.201(a), 201(b), 201(c), and 201(d), upward and downward movement of ahead are executed by a loading motor 516. In FIG. 201(a), the loadingmotor 516 rotates and a tray moving gear 518 moves in a direction 51a,so that loading of a tray 520 starts. In FIG. 201(b), as the tray 520 isplaced in the player, a micro-switch 521 is actuated and therefore themotor is deactivated. Then, the reproduction of a CD starts. In thepresence of a medium identifier the motor 516 further rotates in adirection 51g so that the tray moving gear 518 further advances in adirection 51b. Therefore, as shown in FIG. 201(c), a head moving link503 is rotated, and a head elevator 519 is raised in a direction 51c. Asa result, a magnetic head 8 is brought into contact with a magnetictrack 67a so that the magnetic recording or reproduction is enabled.After the magnetic recording or reproduction has been completed, themotor 516 rotates in the opposite direction so that the tray moving gear518 moves in a direction 51d. Therefore, the head elevator 519 is raisedin a direction 51e, and the magnetic head 8 is moved out of contact withthe magnetic track 67a. Then, the normal optical reproduction isstarted. As previously described, the reproduced magnetic data is storedinto a memory 34 composed of an IC memory, and a data updating processis executed in response to the data in the memory 34. Immediately beforethe tray is ejected from the player, only the updated data (the newdata) is subjected to magnetic recording or reproduction to update themagnetically recorded data.

With reference to FIG. 226, a recording and reproducing apparatus suchas a CD player of the upper lid opening and closing type includes anoptical head 6 and a magnetic head 8 which is provided at an oppositeside of the optical head 6.

In the apparatus of FIG. 226, the optical head 6 and the magnetic head 8can be moved by a traverse motor 23a in a direction denoted by the arrow51. The direction 51 of movement of the optical head 6 and the magnetichead 8 is set parallel with a shaft 521 for opening and closing rotationof an upper lid 389. Thus, there is an advantage in that the positionalrelation among a suspension 41a, the magnetic head 8, and the opticalhead 6 can be accurately maintained when the upper lid 389 is opened andclosed. Thus, it is possible to more accurately access a magnetic trackat a back side of an optical track.

The upper lid 38a is provided with an optical sensor 386. When the upperlid is closed, the optical sensor 386 reads an optical mark on a labelsurface of a CD 2. Only in the case where the presence of a magneticlayer is detected by referring to the output signal of the opticalsensor 386, an elevating motor 21 drives a head elevator 519 to lowerthe magnetic head 8 onto the magnetic layer. Thus, there is an advantagein that a conventional CD without any magnetic layer can be damaged bythe magnetic head 8.

With reference to FIG. 227, a description will be given of a CD playerof this invention which has a playback function for a video CD. Theapparatus of FIG. 227 is basically similar to the apparatus of FIG. 181except for the following points.

In the apparatus of FIG. 227, a moving-image reproducing section 33b ofan output portion 33 has a MPEG video decoder 33e according to the MPEG1standards. A reproduced image-compressed video signal is expanded anddecoded into an original moving image signal by the decoder 33e. Theresultant signal is changed by a D/A converter 33f and an NTSC/PALencoder 33g into an NTSC or PAL analog TV signal, which is outputted toa monitor 449. Audio information is handled by using a level 2 of MPEG1,being outputted as an analog audio signal by an MPEG audio decoder 33iand a D/A converter 33k.

The apparatus of FIG. 227 features that a memory stores a menu-selectionnumber table 522 in which selected numbers are stored for respectivemenu screen pictures in the playback function of the video CD. Amagnetic track 67a of a magnetic recording layer 3 of a recording medium2 is subjected to reproduction by a magnetic record and reproductioncircuit, and thereby a part or the whole of the contents of themenu-selected number table 522 is obtained. Only in the case where achange is present in the contents of the menu-selected number table 522,change data is recorded on the magnetic recording layer at an end ofthis process.

FIG. 228 shows a related data structure. The format of a video CD of aCD-ROM, that is, optical recording is made on the basis of the ISO9660standards in the CD-ROM-XA standards. In FIG. 228, a control signal, amenu, an index of a video CD, and others are recorded on a track 1, thatis, a video CD data track 526. There is a list ID offset table 525 intowhich moving picture addresses 525a and still picture addresses 525b arestored. A playback control portion 523 stores a play list 523a forindicating a sequence of reproduction of moving pictures, a selectionlist 523b for indicating a sequence of reproduction of menu pictures,and contains information for controlling a sequence of playback.

In the case of a CD-HB of this invention, magnetic record data ispresent which contains the menu-selected number table 522 which can beupdated. Accordingly, the previous menu selection number related to theoperator can be reproduced again. For example, in the case of aneducation software, the display image can be advanced to thepreviously-learned final branch point. Thus, there is an advantage inthat it is unnecessary for the operator to input a number again in themenu.

With reference to FIG. 229, operation of the video CD player of thisinvention will be described. At a step 524a, the reproduction of a videoCD is started. At a step 524b, a check is made as to whether or notmagnetic data is present. If it is no, normal reproduction is done at astep 524t so that images are reproduced in a sequence show at a step524u. If it is yes, the name of the operator on the magnetic data isreproduced and a menu picture for magnetic data is indicated forselection of the operator name. If it is no during the use of magneticdata at a step 524d, normal reproduction is done. If it is yes, magneticdata is reproduced at a step 524e so that data of the menu-selectednumber table 522 is reproduced which corresponds to the operator. Next,at a step 524f, reproduction is done according to a branch sequence fora playback control region of the optical record layer. In this case,moving picture addresses are generated from the play list 523a whilemenu picture addresses are generated from the selection list 523b. Atsteps 524g and 524h, moving pictures are reproduced, and an N-th menustill picture is outputted. During that time, at a step 524j, N-th data522n is read out from the menu-selected number table 522 such as shownin FIG. 230, and the number corresponding to the operator, for example,the selection number N−1, is read out. Then, at a step 524p, the menunumber is automatically selected. At a step 524q, a next image isreproduced. If the selection number is not recorded at a step 524k, theoperator is forced to execute selection at steps 524m and 524n. At steps524r and 524s, checks are made as to completion and continuation. In theabsence of continuation, advance to a step 524u is done, and a step 524wprovides a question regarding whether or not the menu selection numberis saved. If it is yes, a check is made at a step 524x as to whether ornot change data is present in the table 522. If the change data ispresent, only change portions of the selection numbers for therespective menus are recorded on the magnetic recording layer and thenending is done at a step 524z. Accordingly, there is an advantage suchthat reproduction can be done depending on the operator for the videoCD.

The step 524u indicates the reproduction sequence for the normal videoCD. This invention is advantageous in that once the number is inputted,it is unnecessary for the operator to input the number again. FIG.231(a) shows picture and audio data structures. FIG. 231(b) shows indexnumbers for MPEG data corresponding to one track.

A description will now be given of a way of accessing a magnetic trackat a higher speed. In the case where a magnetic track is accessed bysearching for a given address as shown in FIG. 232, it takes a certaintime to find an optical address. In the case of a CD, to enable searchfor an optical address at a high speed. “1” is consecutively stored in Pbits of the sub code of FIG. 233 which correspond to about one round.Thus, P=1 is always reproduced and detected when the optical head 6moves along a track 65 as shown by the optical tracks 65a and 65b ofFIG. 232. In this invention, optical tracks 65x and 65y are providedwith magnetic track search information 527 independent of opticaladdress search information 526, and the magnetic track searchinformation 527 is formed by setting T bits of the sub code to “1” whichcorrespond to about 1 round. This design provides an advantage such thata search for a magnetic track can be done at a remarkably higher speed.It is good that magnetic addresses are stored in U bits of the sub code.

1. A reproducing apparatus for reproducing signals from a recordingmedium in which first physical features information indicative of aphysical feature unique to said recording medium was recorded asciphered information, said apparatus comprising: deciphering means fordeciphering said ciphered information to obtain said first physicalfeature information; detecting means for detecting and obtaining secondphysical feature information from said first physical featureinformation; checking means for checking whether or not said first andsecond physical feature information have a specific relationship; andmeans for stopping a specific operation when said checking meansindicates that said first and second physical feature information do nothave said specific relationship.
 2. The reproducing apparatus as claimedin claim 1, wherein said specific operation comprises outputtinginformation reproduced from said recording medium.
 3. The reproducingapparatus as claimed in claim 1, wherein said specific operationcomprises an operation under control of a program reproduced from saidrecording medium.
 4. The reproducing apparatus as claimed in claim 1,wherein a public key cipher key is used, in said deciphering means, as akey for deciphering said ciphered information.
 5. The reproducingapparatus as claimed in claim 4, wherein RSA cipher is used as saidpublic key cipher key.
 6. A reproducing method for reproducing signalsfrom a recording medium in which first physical feature informationindicative of a physical feature unique to said recording medium wasrecorded as ciphered information, said method comprising the steps of:deciphering said ciphered information to obtain said first physicalfeature information; detecting and obtaining second physical featureinformation from said first physical feature information; checkingwhether or not said first and second physical feature information have aspecific relationship; and stopping a specific operation when saidchecking means indicates that said first and second physical featureinformation do not have said specific relationship.
 7. The reproducingmethod as claimed in claim 6, wherein said specific operation comprisesoutputting information reproduced from said recording medium.
 8. Thereproducing method as claimed in claim 6, wherein said specificoperation comprises an operation under control of a program reproducedfrom said recording medium.
 9. The reproducing method as claimed inclaim 6, further comprising a step of performing a specific display whensaid checking step indicates that said first and second physical featureinformation do not have said specific relationship.
 10. The reproducingmethod as claimed in claim 6, wherein a public key cipher key is used,in said deciphering means, as a key for deciphering said cipheredinformation.
 11. The reproducing apparatus as claimed in claim 10,wherein RSA cipher is used as said public key cipher key.
 12. Areproducing method for reproducing video signals recorded in a recordinglayer of an optical disk in such a manner that tracking variations areformed at an address position in a circular or spiral track comprising:disk driving step of rotating an optical disk; an optical head operatingstep for emitting a light beam and receiving light from said opticaldisk to read information recorded in said disk in the form of pits;tracking controlling step of effecting tracking control so that a lightspot on said recording layer of said optical disk resulted from saidlight beam follows a series of pits on a track of said optical disk; atracking amount detection step of detecting from a tracking amountsensor an amount of the tracking variation in the address position; adisk checking step of properly judging whether the current disk is legalor illegal according to the distribution of tracking variations,comparing the amount of the tracking variation with a tolerance value,wherein said tolerance value is set so that the current disk is judgedto be legal if the amount of the tracking variation is within thetolerance and to be illegal if the amount of the tracking variation isoutside the tolerance; reproducing step responsive to an output signalat said optical head operating step for reproducing a video signal; andan output/operation stopping step of stopping outputting of videoinformation reproduced at said reproducing step to be externallyoutputted or stopping said reproducing step in accordance with said diskchecking step.